HOW IT ALL STARTED

This fic takes its inspirations from so many fanarts (for me at least) circulating out there about a situation similar from the one the Kamado siblings go through in the canon of Kimetsu no Yaiba. So, the plot parts as well from the original concept of Koyoharu Gotouge. The rest of this fic, as little as maybe be, I claim it as my contribution to this fandom I like so much.

Tsutako had finally finished the arrangements of her wedding with her future in-laws. Just in time for taking a short break before everything happen. She was not so sure of how this would sit for her little brother at all, but she was confident that her marriage would be a positive thing for him given their circumstances. Their parents were gone, and even if there were some relatives out there, it was difficult to say they were there for them. She needed to find a husband and had a family. And even in her situation of no parents and a little brother that could be seen as an unwanted son for her new family, that was not the problem. She already had attracted the attention of a suitor to the point of securing a fiancé. She was near to have what she needed and must have. Her soon-to-be husband and his family had accepted them as they were. They were getting married the very next day. So, why that feeling of uneasiness? Perhaps the reason was she left her little brother all alone back home.

She knew it wasn't responsible of her to do that, nor even nice, but she thought it was best that way. Some days she left him behind because she thought she wouldn't have the time to look after him with all the things she needed to attend and discuss, especially with her future mother-in-law. She was going to be the newest member of the family and she needed to be prepared. However, that day the reason was a little bit different. Her friends had insisted to gather one last time given it was her last time as a single woman. It was her last day indeed, free of all the responsibilities and troubles that the married live brings. After her wedding, she would never be able to stay like that with her friends. So, she agreed to the plan and stayed with them more than she should. A little part of her yearned for her little brother, trying to remember why she hadn't brought him with her. At the same time, another part of her wanted to treasure that moment knowing it was her last. She would sacrifice many things and say goodbye to some others. In a way, it was saddening to just think about it. So, she ignored her worries and allowed herself to enjoy a little bit more the gathering. She did it promising herself to return home soon, before the darkness arrive. But she got distracted enough to end up losing track of time.

When she realised what time it was, it had already become very dark outside. Too late to even tried to go back home in the middle of the night. So, for the sake of her, her hostess offered her a chamber to pass the night. Tsutako wasn't sure if that was ok. But her friend insisted. After all, it was too late to risk her safety. Plus, she needed to preserve her honour and dignity as a young lady soon to be married. Her brother could take care of himself for one night. He was old enough to do things on his own. He was going to be alone anyway once Tsutako leave him to live at her husband's from the next day onwards. If it was for her schedule, that wasn't a problem. She would return on time. She didn't even live too far. She would be able to prepare herself even if she needed to do a little in advance at the place, she was currently in. Her hostess would be happy to help her. Tsutako found all that a little too complicated. Of course that would result easily in disaster! But she ended up complying with the arrangement. Never uttered another word of disagreement. She convinced herself that, upon her return, she would find Giyuu all right. With that she tried to mitigate her anxiousness. She was going to apologize to him first thing in the morning. He was no baby, so he should be fine, right?

But that was her mistake. That night Tsutako tried to sleep in vain. Not a wink of sleep for her that night. It was the night before the day of her wedding. Of course it was a very important day for her. Most of the women would agree with that. But she was going to remember it for a whole different reason. The feeling of guilt would accompany her for the rest of her life.

⁂

Tsutako didn't need to be exactly in front of her home to know something was off. The moment she got a glimpse of it from afar she shivered uncontrollably. That morning, she woke up early and didn't accept to take the breakfast her hostess offered her. She ran back home the moment the sunlight was enough to see where she was stepping. She was excited for the importance that day had for her. But she was more anxious for her little brother. Her alarm skyrocketed when she didn't find him anywhere near the entrance. Her little brother wasn't waiting for her anywhere. She was sure he could hear anyone approaching from that distance. Was he still asleep or distracted by something? She couldn't even hear him inside the house while nearing the entrance. The silence that welcomed her was so heavy, like a graveyard, to calm her worries in any way possible.

"Tadaima!" She cried to assess what was happening, hoping the problem was she arrived too early in the morning for her little brother to come out and greet her. "Giyuu, I'm home! Sorry for leaving you for so long. I guess you were worried. A lot of things happened and..." She froze immediately, leaving her excuses halfway out of her mouth. "Giyuu?"

The inside of her home wasn't a mess. For a better description, it was like someone had tried to kill a fly with a hammer and failed miserably multiple times. The smell of blood was faint, but recognisable enough to pinpoint where the victim of the massacre was. One pair of bloody red footsteps coming from the same direction painted the floor, for sure they belonged to an adult. They were the sign that someone had stepped out the house living behind despair, perhaps death.

"Giyuu, are you...?" alive was the word she wanted to utter but she couldn't find the strength to pronounce it aloud. Instead, she ran in the direction of the faint smell. "Giyuu, let me know if... No, Giyuu, what happened?"

There, in the middle of their tiny dining room was her little brother lying on the table, bathed in his own blood. Tsutako rushed to him in hopes of finding some warmth or faint breathing. Something that told her that her little brother was still alive. She inspected him thoroughly and found the signs she was looking for. He was only unconscious. She didn't know a lot of medical procedures, but she knew enough for providing some first aid. Her little brother's left arm was scratched, also a deep cut in his neck was still bleeding. His torso was covered in bruises. Tsutako suspected some broken ribs, perhaps his right femur too. But nothing too bad to prevent her of moving him. Or at least she hoped for not worsening his condition by carrying him all the way to the nearest doctor available. The blood and her inexperience made difficult to assess anything conclusive.

"Don't worry, otouto. I will save you. Anyone won't threaten you again!" she murmured more to herself than to her little brother. "You won't die like this." She promised.

She ran frantically out, her little brother on her back, returning to the village in record time. Or that was her intention. Half the way into the village, her little brother awoke and started to squirm. Tsutako couldn't properly see him, but she was sure he had moved his hands in a strange fashion. In a way that she believed she saw claws in the place of his nails nearly scratching her face. He growled and twisted with increasing force each time he moved his supposedly broken body.

"Giyuu, please don't move like that! Your wounds will worsen if you do. Giyuu!?"

She couldn't say anymore. Her little brother tackled her in a blink of an eye. Tsutako could have evaded that. But lost her footing instead because of her attempt to prevent more damage to his body. Thrown harshly to the ground, she could finally appreciate his appearance. Yes, he had claws. He was showing sharp teeth. He was getting stronger and bigger by the second. He was attacking her without a doubt. The only thing she had on her for any means of protection was a fan and a small dagger that couldn't be of much use right know. But she threw both into his wide opened mouth in hopes of restraining his advances as much as she could. She knew she didn't have the strength to stop him, neither for getting him off her. He was way too strong for her to do anything. Her only option was to buy some time and make him come to his senses, or soon he would outweigh her. Only the gods knew what he would do next.

"I'm so sorry, otouto. I didn't intend to abandon you last night. Never imagined that you would have to go through so much suffering. I should have brought you with me, or at least stayed with you." Tsutako felt her tears going down her face. "I'm a horrible big sister, Giyuu, but I want you to recover and be safe..."

Suddenly tears that weren't her own touched her cheeks. Surprised Tsutako realised she wasn't the only one sobbing. Her little brother had reacted, her words had reached him. And then he was back to her cute little brother. With the addition that he wasn't bleeding or seem hurt anymore. Only dry blood remained. That was when Tsutako concluded that something very sinister had paid a visit to their home that night. Her only relief was that he was calm, the killing intent abandoned. That didn't last long. Immediately her little brother became alert and adopted a defensive stance. Turning to face the danger. Tsutako looked up and took notice for the first time that they weren't alone. Their fellow villagers, some of them their neighbours, where looking their way in a judgemental manner. She stood up to have a better view of the situation. Fear and horror shone in their eyes. Their mouths puckering like they were watching something repulsive. Perhaps they were exaggerating their point of view of their predicament. Perhaps they were too prejudiced to understand their situation. Anyway, Tsutako remembered just then that that day was the day of her wedding. And she should be preparing for the occasion, not making a scene with her little brother in the middle of the village, too early in the morning.

"Gods, why this?" she muttered.

Then, the attack began. The first rock never hit her. Her little brother stopped it in a flash and threw it back with such force that it scared the villagers enough to stop them and make them retreat a few steps. Tsutako feared that, upon understanding their disadvantage, they would resolve to gather weapons and reinforcement for confronting her little brother better. And she didn't know how long her brother could last protecting both, or how strong he was to face the villagers. Despite that, she believed her little brother noticed something else because he started to panic looking at the horizon. Torn between abandoning his position before their attackers or staying where he was till the very end. Tsutako quickly decided that her fiancé and her wedding could get lost in the path of life. Her little brother's life was so precious to be wasted for something like that.

"Let's get out of here now that we have the chance, Giyuu" she suggested, and didn't need to add more.

Upon hearing her, her little brother stopped hesitating and took her in his arms like she was as light as a feather. Then, he ran in an inhumanly speed out of the village. He took both to the nearest forest and went deep enough like he was scaping certain death. Tsutako didn't doubt the villagers, with whom they grew up alongside them, would think twice before hurting, even killing him or the two of them. The look on their faces was enough proof of something like that. She never protested while her brother took her into the unknown. Her instincts told her that she could trust him, and that he was doing the right thing somehow. The problem was she didn't understand his behaviour. What was clear for her was that they weren't returning home. It was dangerous and doing so would be stupid from their part. So, the question remaining to be answered was: what were they going to do then? Their actual prospects weren't in any way what she had envisioned all those past years for their future. Why anyone took their side and protected them? It was obvious for every angle that they weren't dangerous and certainly in trouble. Where were at least one of their relatives when they needed back up? Were they worried for them? Only some years after, while revisiting that moment, she would be comforted by the absence of the only people in the world that could've made a difference in their situation. The absent Demon Slayer sent to do their duty. Whatever prevented one of them showing up that night and the next day had saved two lives. One of them was her little brother's for sure.

⁂

When Urokodaki smelled the intruders, he found it difficult to grasp the situation. One clearly smelled like a demon, but his intentions weren't of one readying himself to attack. He wasn't hunting. He wasn't sizing the field. Even more incredible, he hadn't eaten a single human since forever. No, he smelled of desperation. He was crying out loud for help without emitting a single sound. And that was the more intriguing part, he wasn't alone. He was accompanied by a human. A female terribly ill and on the brink of death, or nearly that state. They were approaching his mountain without intentions of forcing themselves upon him. At least not in a so violent way. He could assess all that from what the demon was smelling. The girl probably was too sick to even realise anything. So, he decided to see what they were up to and prevent his student from their presence. He wouldn't risk his young life just because of a coming-in-peace visit.

"They aren't planning on attacking us. That's why I don't want you to start the offensive. Although, stay alert just in case, Sabito" he instructed him before stepping outside his cabin.

Urokodaki found them not to far from his home. The demon may had sensed him and his resolution. Perhaps he had decided to show him how harmless he had the intention to be. The retired Water Hashira wasn't sure of what was the best way to face him but decided to play along. He was confident a young, uncorrupted and inexperienced demon couldn't be a huge deal for him and his student. No matter how old he looked, he was sporting the image of a young man, he certainly was a newborn as a demon. What intrigued him the most was the girl that the demon was carrying like she was his most precious possession. She was trembling in fever and from the smell of it she hadn't already received the proper care.

"Are you looking for help?" He asked. More like a statement than a real enquiry.

The demon nodded eagerly. Urokodaki smelled his plea, and the absence of a hidden second intention. For all he could get he may be keeping his human consciousness. But how? And more importantly, for how long? He sensed he could trust him but couldn't determine how far his trust could be given. Kind of domesticated or not he was a demon after all. And demon's temperament was volatile. One drop of blood and it was a certain game over.

"I can help her and I'm going to do it, but I need you to promise me that you won't attack us" Urokodaki resolved as the conclusion of a quick calculation.

The demon looked offended but accepted his condition with a solemn nod.

"Follow me, then" the cultivator turned around and vegan to run knowing the demon could easily follow. "I guess you already know I had company. Please behave yourself around him."

He smelled some resignation accompanying the acceptance of the demon. That was enough for him for the time being.

When they returned, they found Urokodaki's student waiting for them sat near the entrance of the cabin. He didn't look pleased when he got a glimpse of their visitors but said nothing about it. For his part, the demon studied him with some apprehension. Urokodaki was sure he felt the tension emanating from his student in a higher quality than him and his refined sense of smell. But the demon resolved to ignore the hostility and turned to him as if asking what he can do there.

"Take the girl to this room" Urokodaki instructed him. "Sabito, please, bring some cloth and water. She's burning. We need to cool her down before it's too late."

While tending the poor sick girl Urokodaki asked himself if that was necessary. After all, it would've been easier to kill the demon and keep the girl until she gets better. He knew their kind enough to know what to expect from them. Despite that, he was sure that the moment he met with those two something told him that perhaps, only perhaps, it was better to admit them than to reject them. The problem was he didn't even smell a reason why.

⁂

The days following that encounter passed with no altercations from any of the parts involved. At Urokodaki's instructions, his student didn't attack the demon, but he made crystal clear his contempt, that he wasn't approving the situation. It was understandable for the retired Hashira, but difficult to bear for the demon. Despite his promise, and only for precaution, Urokodaki got him to wear a mask covering his mouth. The demon didn't take it kindly but tolerated it with an admirable continence, focusing on the human girl and ignoring the rest. He only diverted his attention once and that was for stating their situation as he could comprehend it. Even if he didn't speak a single word, he managed to tell them his story. The recovering girl was his older sister. He somehow fell in a kind of slumber, from which he awoke in a state of confusion. When he regained his senses, his older sister was trying to talk to him, worried. He couldn't comprehend how, but he managed to grasp the dangerous situation they were in and protect both from their fellow villagers. They were attacked for some unknown reason, but they managed to escape. After that, they wandered through the forest till his sister fell ill. And he passed his days tending her as good as he could figure out and his nights looking for help. He ran into the traces of someone living in that part of the mountain while doing so. He sensed he could trust Urokodaki and approached him. The story had a lot of holes and missing parts, but for the retired Hashira and his student that was enough to believe him. Urokodaki didn't smell a lie. And his student could sympathise with them in some point. A demon attack was a given and his transformation could had had erased the vital facts from his memory. The tale was coherent enough. Until the recovery of his sister, they had to be satisfied with that. All in all, it was a miracle he was capable to take care of her and even make sense of the general facts while engulfed by the mist of his transformation into a demon.

Day by day, the demon could be found besides his sister. Sometimes he took upon himself to mimic the basic ritual of taking care of someone burning in fever from Urokodaki. Others, he would sit at a corner of the room she was in and observe whatever Urokodaki or the doctor who came twice to check on her did. Most of the time he could be found sitting right next to the girl, her hand in his and mulling some kind of song. His sister has been mumbling in desperation about abandoning someone and promising that she would take better care of him. The promises seemed to be made to someone that wasn't there anymore for her. Urokodaki supposed that she was hallucinating, and her little brother was responding to her, perhaps trying to console her in the best way he could. The result was his incoherent singing. Something probably part of a nebulous memory of his, because he rarely stopped once his sister's monologue began. Also, he rarely moved a single additional muscle apart from the necessary for one activity every passing day. Every morning, he would cover himself the best he could with some clothes and blankets that could protect him from the sun even inside the cabin. And every night he would uncover himself to be able to stay a little freer. Urokodaki's student lost his patience more than once seeing him doing all that and nothing more. A clear signal that he had stopped seeing him as just a threat and nothing more.

"Hey, don't you have something better to do than waiting? Aren't you hungry?" He shouted at the young demon every time he could, that meant every day before and after his training sessions.

But he always received the same response: silence. Like he never said a word towards him. Urokodaki told him each time that the demon wasn't to be disturbed. They didn't know how he could react given he was, after all, a demon. Specially a demon in the process of defining his new personality in his new life. His tantrums, if it was a chance for him to react like that, would be far worse than any human could deliver. Urokodaki didn't smell aggressiveness or malice, not even hunger or a killing intent. The demon was peaceful, and very humanlike in his own way. Just like if he was a young boy trying to appear like an adult. It would be wise to help him keep that mood. Urokodaki would try to talk him into protecting humans from other demons, but he wouldn't do more than that. Also, he had reached a deal with him, and the demon wasn't breaking his word. But his student wasn't listening any of it, he wasn't satisfied with something.

"You! Are you sitting again waiting everything would fall into place just because? Perhaps you can't do much for her, but what if… What if she never awakes? Would you lose it because of that?"

His student had changed the words he usually threw every time he could. And those had struck hard the poor demon, but he restrained himself from attacking the rude boy. Urokodaki appreciated the young demon's show of control. And dimed his student's behaviour out of place despite being thrown to the very kind of creature that this young human swore to hate and exterminate.

"Sabito!" Urokodaki warned "That wasn't nice of you."

"No, he needs to think, Master" insisted his student. "He's the strongest out of the two of them and yet he seems lost without her. What if she survives this but got attacked by another demon? She has been blabbering about abandoning someone, yes. But her promises implied that her live has always been decided for the sake of that same person. I won't be surprised if she ends up sacrificing herself in some way or another for that person even after he was turned into a demon! All her efforts will go to waste just because he can't do anything with it! She doesn't deserve it either way, alive or dead."

"Sabito, stop harassing our guest" demanded Urokodaki, but the demon beat him to do something more.

To his surprise, the young demon took his sister's hand to his heart and stayed that way for a second. Then he banished only to appear mere seconds after in front of his student with a furious gaze. He didn't exudate hatefulness, but he was angry, offended and a bit ashamed. To Urokodaki's student's credit, who was a bit misplaced for the demon's reaction, he didn't move one step behind. He stayed his ground, waiting for an attack that never came. The demon contented himself by bumping his shoulder with the other's and returned to his sister. He did so with the lesser force he could muster, like he never forgot, in the middle of his outburst, with whom he was dealing. But it was likely that that gentle touch would leave a bruise difficult to heal as the aftermath.

"At least you listened" was all Urokodaki's student replied after that.

The very next night after the confrontation, the young demon was seen by Urokodaki sitting outside the cabin, looking at the stars. He was meditating something, but he was very indecisive. He was lost on what to do about something. Urokodaki didn't want to interfere much but sat down beside him and talk a little bit about the dangers lurking outside, especially in the night.

The next morning, his student appeared with some water for the young demon's sister before training. Something had changed. Urokodaki could smell it clearly.

"If you can consider humans as something more than just mere food, I'm ok with you. I'll stay that way as long as you don't eat or hurt any of us, humans" he sentenced while offering a shake of hands. "I can't believe I'm doing this, but a man should be fair with the good, er, beings."

The demon accepted his offering with certain dubitation. Urokodaki was sure that was the beginning of some kind of truce between them. And thanked the end of the open hostility going and coming between those two.

⁂

His suspicions got confirmation later, when his student shifted his training schedule and he could be seen at night followed by a young-looking demon. Apparently, the demon had assumed his original appearance. He looked much younger than what he made himself look like the night of his arrival and during his stay until then. He was about the age of Sabito. Urokodaki felt pity for him. Such a young age for being turned into a monster, and having to deal with so many things must be hard. But he was doing his best to do the right thing.

"It's good to see both getting along." He commented to the pair when they were returning after their nocturnal practice.

"I guess he can learn a thing or two if he was to carry his sister with him, Master." Replied Sabito with a shrug.

The demon only nodded, like he was accepting a well-known fact, but Urokodaki smelled him more alive than before his outings. He wasn't exactly learning from his student the Water Breathing or anything, or perhaps he did but that wasn't his focus. The cultivator had supervised their exercises here and there. Instead, the demon kind of help his student in his training, like offering himself as a realistic simulation of what he can faced in a real combat. Urokodaki appreciated the advantages for both and was sure his student did the same. The young demon would need it too to protect her sister from other demons. His student needed to understand how a demon moves. Their prowess was outstanding to the point that, when the demon's older sister recovered completely, the duo was inseparable and a force to be recon.

"I'm happy that you have made friends, Giyuu." Was the first thing she said once on her feet.

The story came complete with her. Her name was Tomioka Tsutako. Her little brother, Giyuu, got attacked one night while she was out, busy with some friends, just before the day of her wedding. She found him in a very bad state and hurried to take him somewhere to be attended. That was when everything turned for the worst. They had no remaining family who had rushed to admit them at home. So, the moment the villagers comprehend whatever they did that day, they automatically were left alone and to fend for themselves. They even attacked them. Certainly, they were sentenced to something worst, but they manage to escape that fate thanks to Giyuu. Tsutako had left behind her engagement, and everything that came with it for their safety, especially for protecting her brother.

Since they had nowhere to go, and she was left with the need to cure her little brother, Urokodaki offered her some training, suggesting that the one who turned her brother would be the only one who knew how to turn him back to human. If she could learn the Water Breathing and pass the Final Selection, she could get a step nearer that very demon, Kibutsuji Muzan. Tsutako heard him explained himself carefully. Urokodaki smelled from her a little bit of uncertainty mixed with conviction of giving a try at the very least. Giyuu exuded determination, like he was in whatever his big sister and new friend would decide to get involved with. Urokodaki smiled fondly behind his tengu mask. Perhaps the generation that could defeat the Hand Demon had finally arrived. Perhaps, Oyakata-sama would get soon not one, nor two, but three more children that would help him in their common objective. He just needed to wait and see what future awaited his protegees. Urokodaki prayed for them that it would be a bright and happy one despite knowing fate had already decided what would await each of them.

⁂

If he was honest, Sabito had to admit he was impressed. Since his master took the unbelievable decision to admit a demon in his domains, his world had turned upside down without a warning. At first, he wasn't happy with the accommodation. A demon carrying a human just because he was worried about her was a sight to be seen. He wouldn't have believed it if he hadn't seen it with his own eyes. But his master was convinced of his perception of him through the smell the demon exuded the whole time. Sabito didn't have much choice than following his master's instructions and tried to not cause trouble. Then, the demon tried to tell them what had happened to him and the human. And the unrealistic situation took a turn for craziness. What on earth had happened with those two? A demon keeping an essential part of his humanity was something unheard of. His sister, because she refused to recognise him by anything else, had managed to keep him grounded. Then, the demon showed commitment to not be a proper demon. Sabito was baffled but ended up giving his full trust and got a partner for his training in exchange. It felt so much more realistic sparring against him than trying to do so with his master or practicing all alone. Demons can regenerate themselves. With that, Sabito could concentrate on his own performance as long as he didn't touch the demon's neck. In the end, he ended up trying not to slice him by accident or hurt him in any other way. And later, when the demon's sister awoke, the two of them got names and a proper story. Sabito wasn't sure they were lucky, but at least they were determined to go on and do something useful with their lives.

Since then, Tsutako started her training. She lacked physical condition, but her dedication supplied enough for her training to start to pay off. It was understandable that she started her training in daylight. The basics must be learnt when she could sense everything clearly. And she was doing ok. Her muscles ached and she gained some bruises and cuts here and there. But she was gaining agility, strength and flexibility. Anyway, Sabito had to endure seeing Giyuu's anxiousness showing every time his big sister returned home. He didn't need a super smelling ability to sense that. It got worse the day she returned home socked to the bones. Sabito found it ridiculously funny but tried to not show it. That day Giyuu didn't calm down until his sister told him it was enough, that it was part of the job. Their routine fell into place quickly, the boys trained at night and Tsutako prepared herself the best she could to join them during the day. They spared, she made some laps and descended the mountain every day. Sabito took upon himself to give her some pointers when she started to practice the forms of the Water Breathing. Everything under the watching eye of their master, who seemed pleased with their arrangement. Soon enough, Tsutako joined them in their training. This cheered Giyuu up for a while, because he discovered for his horror that he had to attack his sister. That didn't sit well with him.

"Come on, Giyuu. I can't be as half as good as Sabito if you can't help as you do with him!" one day Tsutako reached the limit of her patience and recriminated her little brother his way of treating her in training. "I know you don't want to hurt me, and I'm glad you think that way. However, I'm not going anywhere if you keep disrespecting my ability to fend for myself."

Sabito sensed the turmoil in his friend, but recognised Tsutako's claim was right. She couldn't afford to be weak in a job like the one they were pursuing. It took some time for Giyuu to come to terms with it and be the same during their sparring. But their worked together continued to the pint they were sure there was little they could do to reach beyond given their circumstances.

"No, no. That's not the way you do it, onee-san." Sabito pointed out one day. "You need the movements, yes, but a mechanical repetition simply won't do. You must engrave them into your flesh and bones. They need to be natural as breathing. You do it when you need it, without even thinking."

"At this point I'll fail terribly before I can strike a demon. I'm not talking about you, Giyuu." Replied Tsutako looking frustrated.

"No, that's not it." Sabito refuted trying to not lose his cool. "You only must lift the burdens you cast over you. They're unnecessary, onee-san. You have strived to be where you are now, and you have showed dedication and tenacity. I'm sure you can put demons in a dire position, just don't give up."

Being in such a company, the time flew quicker for Sabito. To the point that the day their last test arrived came unannounced.

"This is your last test." Urokodaki informed them. He had taken them to a part of the mountain they rarely visited. "These boulders are hard to be cut by a sword, they can easily break as you already know. So, your last exercise for being allowed to assist to the Final Selection is to cut this boulder without breaking nor damaging your sword." And walked away without adding anything else.

"Well, I supposed I'm good enough to do this." Sabito heard Tsutako's words of encouragement. "I must do this if I want to cure Giyuu."

Sabito smiled, he wouldn't chicken out just because the task given to them seem impossible at a first glance. It must be a way to do it. Otherwise, the Slayers' weapons wouldn't be swords.

"Let's man up and give our best, onee-san." He proposed. "Let's see who slice their boulder first."

⁂

Sabito and Tsutako sliced their respective boulders just in time for the next Final Selection. That day their master celebrated the conclusion of their training with a feast. Giyuu was with them, of course, but for obvious reasons he wasn't eating. He had to step out when they got the task of slicing their boulders and resolved to sit near them looking how they achieved their goal. So, he was happy to be part of something they do, despite they would part ways the very next day, He also wouldn't undergo alongside them the final step for becoming a Demon Slayer. He would wait their return in the company of their master. Experiencing his own challenges for all Sabito could understand. And even if Giyuu wasn't happy with the imminent separation, he didn't make a fuss. He only wished them good luck in his own style and buried himself under the covers he usually employed to effectively cover himself from the sun. Sabito promised him in silence to do whatever he could to make sure Tsutako return to him. At that point he appreciated the demon. Something he couldn't explain himself why. Despite Giyuu was a whole mystery on his own, Sabito felt a connexion with him he couldn't deny. In fact, in the time they had shared, the Tomioka siblings had somehow become his new family. And the feeling was mutual, he felt it.

"Eat as much as you can, that's the way to gain energy and get stronger" their master told them that night. "Demons are just like us in that respect, but they can recover for nearly every wound and develop extra protection. Be always prepared to encounter anomalies, traps and tricks."

Their master also gave them Kitsune masks as a token of protection. Tsutako and Sabito accepted them figuring out they were given something more than a mere lucky charm, like an unspoken task that very moment. But neither guessed its content or solution. Anyways they did promise in their respective hearts that they would made their master proud no matter the difficulties. They would return to him and Giyuu. That was something they didn't have the intention to fail.

⁂

Tsutako felt something was off the moment they step inside the perimeter of wisteria trees. Seeing Sabito flying and slaying every demon that got in their way, was unnerving. What the hell was going on with him? The demons came quickly smelling fresh meat, but it wasn't like any of the candidates where uncapable of fighting for themselves. At this rate, Sabito would buy them the ticket to their admission to the Corps with nothing more than being mere spectators of the annihilation he was delivering. She, as the rest of the applicants, was in awe at his performance. He was quick and agile, cunning and gifted. However, he was only one against a very large number, so there and then she needed to protect herself. Nothing fancy, nothing much, but at least she did some exercise. To the point she began to understand the purpose of the Total Concentration technique and how to use wisely the ten forms of her breathing style. Sabito had insisted on this last part, but honestly, she understood it at all when the real thing happened. She grasped soon the logic of all of that, if she could say there was a logic inserted in all that fighting. The techniques she had learnt must be engraved on to her very flesh and soul if she wanted to survive, even more if she wanted to ascend ranks and meet that Kibutsuji fellow. So, she must've got out of there with something more than what she had since the beginning.

The time went by on Mt. Fujikasane. Four of the seven days had already passed when the group began to disperse. Groups of four or five took their leave. Others decided to go solo. Everyone gained some confidence seeing the number of demons had diminished considerably all thanks to Sabito's doing. But a considerably few stayed behind with Urokodaki's students. Some among them were also Water Breathing users which make the situation even more interesting. The feedback was priceless for Tsutako. But the group didn't last long. She was dealing with an opportunist demon that had jumped on them while Sabito was distracted with his own problems when the cry of help resounded through the forest. She hurried herself to decapitate it the moment she sensed his brother in training answered the call. Something telling her she couldn't let him take that mission alone. Once she made sure everyone was in conditions to continue fighting on their own, she rushed behind Sabito. No one followed them. They didn't need backup anyway. Something told her that cry had something to do with the unspoken task they were given. But she prayed it was only her imagination without slowing her pace. Her hope didn't last long. When she heard someone's speech, she stopped quickly before reaching Sabito and the victim.

She couldn't comprehend all what was been said, only enough to assess the situation. That demon was expecting their arrival. In fact, he was awaiting any student of Urokodaki to pour out its frustration on them. Meaning in this case it promised itself to feast with any of them it could encounter on its way. Tsutako felt suffocated and her legs failed her. This was a very hard task indeed, but she refused to think bad of her master. The final blow came when that thing began to recount his latest Water Breathing meal. The revelation hit Tsutako hard. A girl younger than her… blinded and hindered by her own emotions. That made sense when compared with her previous reflexions. Overcoming her commotion, she collected herself. Despite her feelings, she resolved to face that thing in the name of her fallen fellow Water Breaths and, most importantly, to not scape her duty. That would be her life if she got out of there alive. That was the only way to meet the demon that had turned her little brother. She couldn't run away if she was going to be the one who would protect others from demons or pave her way to Kibutsuji by fighting this kind of creatures. So, she thought, it was the same if she started right there or await till the Final Selection end. The difference was only time. And, on top of all of that, this demon was her assignment as much as was Sabito's after all. So, she steadied her breath and ran towards the demon just in time to interfere with its hand's attack.

⁂

Upon slaying his first demon, Sabito could realise the huge difference between Giyuu and the demons he was facing right there. That allowed him to appreciate the considerable portion of humanity, and perhaps inexperience, his demon friend was holding against all logical reasoning. There were a few things he was noting as completely new. First, those demons he was fighting weren't newly created. Although, that didn't mean they were the opposite, seasoned warriors. Second, of course, those monsters had eaten all their short or long demon live what they were supposed to feed themselves. Some of them even had devoured more humans than the number of which Giyuu had the chance to interact with. Then, third, it was evident that they had wandered till then in the forest without keeping their humanity. Sabito didn't doubt, not even once, that they were driven by pure instinct, something animalistic, primitive, raw. He couldn't find the exact words to describe it. The blood lust was blinding them to the point of not allowing them to have a single thought, not having the slightest idea of what an incredible thing was strategy. They were throwing themselves, even hampering one another in hopes of monopolizing the tasty fresh treat with such animosity that they were nearly reaching a state of insanity. So, Sabito concluded that despite the wonderful help he had received from his partner in sparring, Giyuu couldn't provide him the authentic experience of facing a real demon.

But that wasn't a big deal. Giyuu had given him a head start. With that, Sabito could keep up and adapt. The demons facing him weren't something he couldn't handle. In fact, they were easy to read, and he was adapting quickly to every situation he encountered. He thought it was true to the point he believed himself capable of protecting Tsutako and the others. He was confident in his ability. Never considering he was too confident for his own good. After all, out of the two students his master ended up admitting, he was the more experienced. He even had the easiness to grasp immediately what he had to do and replicated it, applied it onto the practice. While training alongside the Tomioka siblings, he had the opportunity to appreciate Tsutako's capabilities, also Giyuu was a good apprentice of sorts. He never looked down on his peers, not even judge as incompetent the other applicants of the Final Selection. Nevertheless, he was committed to never witness the death of someone by the deeds of a demon. Never again if he had the chance to prevent it. He had already promised to make sure Tsutako would return to Giyuu at any cost. However, his incentives ran deeper than a mere feeling of siblinghood. He wanted so badly to be a man, to leave behind the helpless boy that couldn't do anything against the murder of his family. For that accomplishment he needed to be the best. His technique needed to be so perfect that an error could be impossible to be committed. Such an achievement only for being able to bear and do the hard work. In any case, meeting the Tomioka duo made his resolve even more especial. They had become his new family, and he would never forgive himself if something he could've prevented happen to any of them.

Then, once he stepped into the forest surrounded by wisteria trees, he began his mission. One by one the demons left that forest in the only way they could do it, turned into dust. Sabito was relieved a little bit more each time one of them vanished into thin air. The weight lifted even more with each day passing, and each sunrise appearing announcing the new day. He noticed the group was diminishing as time went by. But he was too busy to prevent its dissolution, to do something against it. It would be more difficult if the others dispersed. How could've he reach them if something happened? For his sake, at least, Tsutako never left his side and do some cleaning on her own from time to time. He thought he could live with just that until the desperate cry of help pierced his ears. He swore under his breath. That was exactly the situation he didn't want to take place. Abruptly every sensible thought blew away of his mind. He entered in an automaton mode. Everything disappeared around him, and that person became his sole focus. Something inside him urged him to save that person no matter what. And he bolted to the place he heard the cry came from. He needed to arrive on time. He needed to do just that. And he did.

Upon arriving the surprise awaiting him punch him hard in the face. That thing was enormous, grotesque and full of hands. Its neck even was firmly protected by a pair of arms embracing it. One of its other many hands was clutching a boy by the torso. He was effectively immobilised and only kicking aimlessly out of pure fear. The sword in his hand was useless and upon feeling he was not alone with that thing he let it fall to the ground in his attempt to gesticulate something Sabito wasn't sure what it was. The demon looked at him uninterested. Like he was seeing his regular supper and was only eating it because it was nothing more than it. It didn't give much importance to the reaction of the boy. Perhaps he was too confident by the whole situation. After all, he was way more powerful than the demons the applicants expected to face. So, why panicking over some new arrival? He can deal with them after it was done with the current kid. Or perhaps it was another reason far away of what Sabito could think of. He didn't waste more time assessing the situation. He pretended to free the poor boy in one strike, but the demon had many hands, it couldn't be that easy.

"A fox mask" the thing spoke suddenly, it sounded very excited. "It seems we have another Breath of Urokodaki's haven. How wonderful! The last one wasn't that much of a real challenge, but she was something more than the others. Very agile, indeed. Despite that, she tasted to me just as good as the other eleven." He laughed evilly. "I bet you, as the thirteenth, would be just fine. I hope you won't end up being an emotional one like her, though."

Sabito felt the rage escalating inside him. The grip in his sword tightened. The demon delved in delight just seeing that.

"I always love how all of you take this. Didn't you know?" it added with enthusiasm. "That fox mask is the giveaway for you, Urokodaki's students. He caught and imprisoned me here many years ago, that I have lost count of how many years I have been trapped here. I was so frustrated that I promised myself that any of his precious children that ever cross my way would be my dinner for sure, no matter what. And what did he do with that? Giving you a supposed token of protection that could tell me who you are. That craftmanship is so particular, that it can only belong to him. How considerate of him."

Sabito's thought flew back to his final test, that big and hard boulder cut in half by him, Tsutako and any other student his master could've ever had. And then, he understood his intentions. He had prepared them for this, in hopes for them to defeat that monster and return to him. What better way could be found to prepare them for the real deal once passed the Final Selection? As his students, they needed to finish the work. Sabito was taking it personal. He doubted the demon had only fed with his master's students all this time. He needed to avenge not only his fellow students, but there were also the other cultivator's students.

"I'm amazed you aren't running. Do you think you can defeat me? My neck is thick and hard that it is impossible to cut with that sword of yours. And I have even more hands than you. They served me just fine to take, one by one, every limb of that girl after she lost her stance and footing. She was so blinded by betrayal that…" Sabito couldn't take it anymore and in a swift cut he sliced the arm which hand was holding the demon's current victim.

The boy was hoping of being forgotten by his attacker given it had other things, more interesting than him, entertaining it. Hence, when the arm vanished and he got himself free, he ran as quickly as he could leaving his sword behind. Sabito couldn't remind him of it or rush to return it to him. He knew he couldn't get himself distracted. He needed to finish the demon first, as soon as possible. Thus, he positioned himself to begin what he dimed the most important encounter he would get through the whole Final Selection. He was confident. His boulder, his training, he had what it takes to defeat that thing once and for all. Or so he thought.

⁂

"Everything's all right, Giyuu?"

Urokodaki smelled unrest from Giyuu around the fourth day during the absence of Sabito and Tsutako. The young demon wasn't doing something particularly different of what he used to do, but the uneasiness coming from him was palpable. Urokodaki himself liked to think that he would see his students returning by the end of the seven days. He wanted to stay optimistic, but feeling what the little brother of his student felt… Well, he was having a hard time not feeling hopeless. Because he believed it was a signal just like the pang he suddenly felt. It wasn't something of his doing, then. Giyuu looked at Urokodaki with a blank expression, but he managed to whimper, like he was worrying about a wound that couldn't be healed by any means.

"I know" replied Urokodaki. "I felt it too."

~•~