Kimetsu no Yaiba doesn't belong to me. This story is a translation of another fanfic of mine. I hope you like it!


Muichiro curiously observed the boy who was tending to the wounds on his legs. He resembled Rengoku a lot, and both of them reminded Muichiro of an owl.

"Are you Rengoku's family?" Muichiro asked, curious. The other boy was startled to hear him speak and looked at him.

"Kyojuro is my older brother," Senjuro replied after a while, continuing with what he was doing, finishing up the treatment.

Muichiro tilted his head a little, thoughtful. That would explain the resemblance between the two. It made sense, yes.

"I didn't know he had siblings," the Pillar commented instead, pulling down his pants' legs and getting off the bed. Senjuro had finished treating him.

Senjuro didn't know what to say to that, so he opted to take the first aid kit back to its place and avoid having to answer anything. Hoping he would get the hint and drop the topic.

"You're not wearing a Demon Slayer uniform," but it seemed like the other boy wasn't done talking yet, "Are you not going to participate in the Final Selection?" Muichiro asked, confused. He understood that all the members of the Rengoku family were dedicated to demon hunting.

"I only work here, I'm not a member of the Corps," Senjuro explained, hoping that would be enough. Avoiding the question about the Final Selection.

"Why is that?" the Mist Pillar asked, insisting.

"I'd rather not talk about it," replied Senjuro, somewhat curt, even though he knew it was a bad idea to speak that way to one of the Pillars. But he was starting to lose his patience. He couldn't stand people like that, who meddled in matters that didn't concern them at all.

Muichiro observed him with some curiosity and seemed to realize something, "You don't know how to wield a sword or anything?"

At that moment, Senjuro had to do his best to remember that he was in front of one of his brother's companions. And that, possibly, it would be a very bad idea to lose his temper or answer rudely.

"My katana didn't change color," no matter how many years had passed, remembering that always hurt Senjuro. It was proof that, due to his ineptitude, he could not do the same thing as everyone else in his family.

"I see. You're useless then," Muichiro said, with obvious disdain in his voice.

Senjuro came to a halt and turned around, fixing his gaze on the boy. "What did you just say?" he couldn't believe what he had just heard.

"I said you're useless," the Mist Pillar repeated without hesitation. He didn't care if his words hurt the other boy.

"That's going too far," someone said from the entrance. They both looked in that direction, and Senjuro felt relieved to see that it was Sumiko.

"And who are you?" Muichiro asked, noticing that she was wearing a uniform.

"Sumiko Kamado, Mizunoe," she introduced herself seriously, stating her rank. "But as I was saying..."

"Aren't you Rengoku's successor?" Muichiro wanted to know, remembering where he had heard of her before.

"That's right," Sumiko admitted, frowning, still upset by his words. She wanted to protest again, but it wouldn't be a good idea. But she also didn't think it was right not to defend Senjuro.

"You sounded familiar from a meeting you attended. Have you met Kibutsuji again?"

"You met Muzan Kibutsuji!?" Senjuro, who was unaware of all this, widened his eyes and looked at the girl.

"Yes, a long time ago..." Rengoku had asked her not to tell his younger brother about it, so as not to worry him. And she would have preferred any other scenario in which Senjuro discovered the truth. Preferably one in which Rengoku or she would tell him.

"Have you met him again or not?" Muichiro insisted, not willing to let the topic go.

"No," Sumiko replied firmly, glancing worriedly at Senjuro. The boy's discomfort was very evident.

"Well, if you're done treating me, I'll leave," Muichiro said, seeming disappointed to hear that answer, and completely losing interest in her. He began to walk towards the exit of the infirmary without adding anything else.

"I think you owe Senjuro an apology," Sumiko said, regaining the courage to speak up. Muichiro turned and looked at her, not understanding where she was going with this.

"Why?" the Pillar asked, not comprehending her point.

"You can't just go around calling people useless," the girl tried to reason seriously.

"But it's the truth. He just stays here, doing nothing while we risk our lives fighting," Muichiro contradicted her.

"That's not true. It's thanks to people like Senjuro, who take care of our wounds, that we can keep fighting," Sumiko tried to defend her friend.

"Sumiko, that's enough, you don't have to keep going," the boy pleaded, trying to keep his voice from trembling.

"And to have a girl defend you, could you be any more useless?" Muichiro didn't like people who were like that. Being the brother of someone as brilliant as the current Flame Pillar only made it worse in Muichiro's eyes. "You're embarrassing."

Senjuro lowered his gaze and clenched his fists in frustration. But he didn't protest or try to defend himself against the other boy's words. After all, he was quite right.

Sumiko also didn't say anything else, aware that continuing to defend him would only make the situation worse.

"I have things to do. Excuse me," Senjuro muttered, quickly leaving the room. He didn't bother to look back, but if he had, he would have seen the concern with which Sumiko looked at him.

"I should leave too," Muichiro commented when they were alone again. "See you next time, Kamado".


Senjuro relaxed as he entered his room. The words of the Mist Pillar kept echoing in his mind. The worst part was that he knew internally that he had spoken nothing but the truth.

As much as Sumiko had tried to defend him, what sense did it make to deny the evidence? Yes, he dedicated himself to healing the wounded in combat, but originally, his position should have been that of just another soldier of the Corps.

He should have expected something like this. As much as the girls who worked there had accepted him, that didn't mean everyone else would. And even less so with his brother being one of the most talented Pillars.

He sighed a bit and tried to remember that Kyojuro wasn't to blame for that situation. On the contrary, he should be grateful to be able to help the Corps in that way. By taking care of the wounded.

He couldn't let comments like that affect him. And he shouldn't continue to rely on others to defend himself. First, he had hidden behind his brother, and now it seemed like he was doing it with Sumiko. In that, as much as he disliked admitting it, the Mist Pillar was right.

If he wanted to be respected, he had to learn to be a man and be able to fight his own battles. That way he would also show his brother that he could handle himself, and he would stop worrying so much about him.

He looked at his desk, there, closed, was the first notebook, the one he had finished transcribing. Determined, and with a new goal in mind, he walked towards the cabinet and sat down. He opened the drawer under the table and took out the second notebook of notes.

He would transcribe it, maybe that way he could get information about the Breathing of the Moon and the Hunter's Marks. The fact that his brother knew nothing about it had only served to increase his curiosity.

"Senjuro?" he heard from the door and, turning around, he saw Shinobu standing in the doorway. "I was looking for you, do you want to come with me to the village to buy some ingredients?"

"Yes, of course!" Senjuro stood up and closed the notebook, leaving it on the table. He could take the opportunity to ask her about that on the way.

Shinobu smiled slightly, and the two of them left.


Senjuro held two heavy bags while the Insect Pillar examined the tomatoes at the store. She was looking for ones that were ripe enough to use for that day's meal.

Since Aoi hadn't returned from her mission yet, it would be up to her to take care of those things. It wasn't that Shinobu disliked cooking, but Aoi was much better at it, and unlike the Insect Pillar, she had always been in the house until then.

Shinobu picked up two kilograms of tomatoes and, after paying for them, headed towards where Senjuro was waiting and placed the small plastic bag containing the tomatoes in one of the bags he was holding.

Senjuro grimaced at the extra weight, but didn't protest.

"Thank you very much, Senjuro," Shinobu said then. "Without your help, I wouldn't have been able to carry so much weight."

"N-No problem," the embarrassed boy replied, embarrassed by the Pillar's radiant smile. But, as he remembered what he wanted to ask her, he quickly calmed down and decided to take advantage of the opportunity. "Kocho..., can I ask you something?"

"Sure, of course, is there something wrong?" the woman asked, looking at her interlocutor curiously.

"Well, you see, at Kyojuro's request, I started rewriting the notebooks of the previous Flame Pillars."

"Oh, and have you found anything interesting?" Shinobu asked, really interested after hearing that.

"In the first Pillar's notebook, a type of breathing is mentioned that I've never heard of," Senjuro continued to explain, and Shinobu nodded, curious. "The Breathing of the Moon."

"I've never heard of that," the woman immediately admitted, trying to keep her suspicion at bay.

"Kyojuro couldn't tell me anything either," Senjuro commented, failing to hide his disappointment.

"I can ask the boss at the next meeting," Shinobu suggested.

"Really?" the boy asked, unsure if it was something important enough to ask Ubuyashiki.

"His family has been leading the Corps since its creation. If anyone knows, it should be the boss," she explained.

"Well..., seen that way...," Senjuro admitted, it made sense.

"Don't worry, I'll still talk to your brother first," Shinobu assured him as the two headed back to the Butterfly Mansion.


Shinobu was lying in her bed. It was already nighttime and the woman was unable to fall asleep. She couldn't stop thinking about the conversation she had had with Senjuro hours earlier. It had only served to reignite the doubts that she harbored towards the boss.

Although she didn't want to dwell on it anymore, a small voice inside her whispered that the boss had also hidden that from them. And Shinobu couldn't grasp the reason, why hide the existence of that Breathing Style?

Something serious must have happened, that was the only explanation that made sense to her. And she intended to get to the bottom of it. She sighed a bit, she had become mistrustful.

She turned and looked at the wall. She kept thinking about all that and it didn't seem like she was going to be able to fall asleep soon. She sat up in bed and pulled her legs out from under the sheets. She got up, being careful not to make any noise.

The best option was to take some relaxing infusion and then go back to bed. She had the option of taking some medication to help her sleep, but Shinobu didn't like to resort to that and, whenever she could, she avoided it.

She left her room and carefully closed the door, trying not to make any noise. She didn't want to wake anyone else up, so she walked to the kitchen, taking care to make her steps silent. It was something that she had perfected over the years, and it came in handy when making surprise attacks against demons.

She was in the kitchen, enjoying her infusion, when she heard the front door of the house open. Surprised by that, she peeked into the hallway and saw Giyuu and Aoi in the foyer.

Smiling a bit, she approached them.

"Hello, Giyuu, Aoi," she greeted, speaking softly, but loud enough for the other two to hear.

"Ah, hi, Shinobu," Tomioka replied in the same tone of voice. Aoi also greeted her.

"You must be tired," Shinobu said, noticing the dark circles under the girl's eyes. Aoi, relieved to have that excuse to leave, nodded quickly.

"Yes, if you don't mind, I'll go to bed now," the girl murmured, quickly leaving without looking back.

Shinobu was about to insist a bit to Giyuu to do the same, when she realized something. "Giyuu, have you ever heard of the Breath of the Moon?"

The Water Pillar, puzzled by the question, frowned a bit and tried to remember.

"No, never. Is it a new style?" he asked, curious.

"No, it isn't," Shinobu confessed, biting her lip slightly. Giyuu was one of the oldest Pillars, if he didn't even know that breathing style...

Giyuu looked at her, perhaps trying to figure out what she was thinking. "Something is bothering you," the man concluded after a while.

Shinobu looked at him, hesitating. Would it be okay to share what she was thinking about the boss with him? Giyuu had already disobeyed direct orders by sharing, although it wasn't much, information about his sister with her. But she also didn't want to rush into things, she couldn't forget that the rest of the Pillars, especially Sanemi, were very loyal to the boss.

"I can handle it myself, don't worry," she said, once again smiling.

"Well, but if you need help or there's anything I can do for you, don't hesitate to tell me."

"I'll keep it in mind, Giyuu. Thank you."

The man nodded. "Well, if you don't mind, I think I'll retire to rest."

"Don't worry, you must be tired. Tomorrow you can tell me how the mission went." Shinobu watched as her friend went to the room that had been assigned to him upon arrival.


Hinatsuru was having breakfast in the kitchen with Makio when Kanao and Sumiko entered.

"Good morning!" greeted Makio, energetically capturing the attention of the two girls, who had been distracted talking.

"Oh, good morning," responded Kanao, with less enthusiasm, furrowing her brow. She would have liked to have breakfast alone with Sumiko.

"Good morning!" Sumiko answered, smiling a little, happy.

Hinatsuru observed both girls carefully. Despite seeing them frequently around the house, she had never stopped to have a conversation with them. Although she had not had the opportunity either.

"How are you?" Hinatsuru asked, attempting to make conversation while they finished breakfast.

"Good, waiting for the next mission," Sumiko recounted. They could be notified at any moment. Or by one of their teachers.

"We should keep training," Makio acknowledged. Shinobu had tasked them with the job of breaking a huge rock each. And that was the requirement they had to meet to receive their permission to participate in the Final Selection.

"How's it going for you?" Sumiko inquired, trying not to make a face when remembering the brutal training that Rengoku had subjected her to.

"We're managing," said Makio. Sooner or later, they would break that rock, but until then, they limited themselves to perfecting their technique, practicing again and again the different forms of the Sound Breathing.

Makio, who had already been able to master the Breathing of Total Concentration, unlike Hinatsuru, spent many afternoons helping the other woman to be able to use it.

"We should go now," Hinatsuru intervened, somewhat serious. Makio looked at her out of the corner of her eye and nodded, finished the contents of her cup, wiped her mouth with the back of her hand, and, after saying goodbye to both young women, they left.

"Do you think they'll succeed?" Sumiko asked a while later, while taking the cup of coffee with milk that Kanao was handing her.

"Shinobu thinks so, that in a few months they'll be ready to present themselves."

"I'm glad," murmured Sumiko. She admired how much these two women had dedicated themselves to their training.

"Do you want to train together?" Kanao asked, changing the subject. Sumiko looked at her and nodded right away.

Whenever they could, they took advantage of training together. It also allowed them to spend more time alone together.

"Do you think we should focus on endurance today?" Kanao asked, taking the last sip of orange juice she had.

"Okay, should we run down the mountain?" Sumiko suggested, smiling a little.

"Yes, perfect for me," acknowledged the other girl, leaving her glass in the sink. "Shall we go?"

"Yes," said Sumiko, imitating her and leaving her cup in the sink as well.


Shinobu carefully shook the test tube and examined its contents with a serious expression. She was in her laboratory, having spent her time since the death of the Sound Pillar modifying the poison he had given her, with the aim of making it more potent.

And finally, she had found the formula by increasing the dose of glycine and adding a muscle relaxant. She planned to test it on the next mission and if it worked as she hoped, she would continue making the combination even stronger. She wouldn't stop until she had irrefutable proof that with that poison, she could defeat one of the Upper Moons.

She inwardly cursed her own weakness, if she had been stronger, she could have decapitated demons like the rest of the hunters did, perhaps she could have saved her sister from that fate.

She trembled a little, she had done her best to convince herself that the best thing for Kanae was to die. But that did not mitigate the pain she felt. She shook her head and tried to push those thoughts away, it was not the time to feel sorry for herself.

She had better things to do. She focused her attention again on the poison and sighed a little, she would test it on the next mission and take note of its effects. To be honest, she was eager to try it out herself.

She took one of the smaller vials and poured a small dose of the poison into it, then corked it. She left the test tube in place and headed for the exit. She turned off the lights in the laboratory, opened the door, and after exiting, locked it.

She hurried up the stairs and soon found herself in her room. She left the vial on her bedside table, close to her sword which was leaning against the wall. She never carried it with her when she was there, it was not necessary. And Shinobu wanted to feel safe in her home, besides, the wisteria trees surrounding the estate kept the demons away.

She left the bedroom and went to find Makio and Hinatsuru, although she was not directly instructing them, she still closely monitored their progress.

She almost collided with Giyuu as she turned the corner of the hallway, but she avoided him in time, taking a step back. The Water Pillar noticed her and looked at her.

"I'm sorry," he apologized quickly. "I was distracted."

"You shouldn't have your head in the clouds," she admonished him, although she didn't sound too strict.

"Yes, you're right," Giyuu admitted. "I was looking for you. I was just assigned a mission."

"Already?" asked the woman, surprised. He had just returned from one.

"In Uzui's territory," the man added. "Since his death, it seems that demons have become bolder. The attacks have multiplied."

"Wow," murmured the woman, and at that moment, she had an idea. "I'll come with you."

"Are you sure?" asked Giyuu, barely able to disguise his surprise.

"Of course," said Shinobu, seriously.

"Well, I don't think it will hurt if you come with me," the Water Pillar admitted, quickly giving in.

"I'll go tell Kanao," said Shinobu. "Will you wait for us at the entrance?"

"Yes, of course," the man agreed quickly, and watched as the woman left and headed for the entrance of the house.


Shinobu, hoping to find her pupil in her room, stopped in front of the bedroom door and gently knocked on it with her left knuckle. Seconds later, Kanao opened the door and saw her.

"Is something the matter, Shinobu?" Kanao asked, despite already suspecting what it was about. It wasn't the first time they had received missions at these hours.

"We're going to accompany Giyuu on a mission," Shinobu explained. "In Tengen's territory."

Kanao, confused by this, furrowed her brow. It wasn't usual for them to go on a mission with another Pillar, although, after what happened with the Sound Pillar, it wasn't so strange.

"I'll grab my sword," the young woman said. She would have liked to let Sumiko know she was leaving, but she wouldn't have time. She hoped she wouldn't be angry with her. She went into her bedroom and returned a few seconds later, her weapon already placed on her belt.

"Alright, let's go," Kocho said, serious. She had already taken her weapon and the vial of poison. She planned to test it, if she had the chance, on the mission.


See you soon with the next chapter! Don't forget to leave a review! I would love to hear your thoughts!