Natsu had gained his Demon Slayer uniform, which was in a white bag. After the exams were over, he bid farewell to Tanjiro who was critically injured, Zenitsu who was happy to survive the Final Selection Exams and Inosuke who promised to master Total Concentration Breathing and get even stronger than Natsu.
After going on their separate ways, Natsu didn't want to waste any time walking, so he ran his way back to Rengoku Residence from the Final Selection Exams. He would sometimes take two minute breaks, then run again. It only took him a couple of hours for him to make it back to his town. He slowed down a bit as he had made it within his village, carefully moving pass a number of people within the streets. He happily gasped as he saw the front doors of Rengoku residence.
"I did it! I passed the exams!" Natsu shouted as he had burst through the doors of the Rengoku Residence. The first person to respond to Natsu's outburst was his older brother, Kyojuro, who dressed in his Demon Slayer uniform and was waiting for Natsu's arrival. He crossed his arms and smiled at the door for half an hour prior.
"Big bro, you're early!" Natsu said.
"I am! There's no way I would ever miss my own brother's arrival." Kyojuro said bluntly with a smile on his face.
"Thanks! That means a lot to me."
"Did you catch the name of the first demon you encountered?" Kyojuro asked.
Natsu nodded. "I did. His name was Oda." Natsu informed his brother Kyojuro about the demon he fought during the Final Selection Exams.
"Oda, you say? That's great!" Kyojuro let out a fist. Natsu saw this and quickly bumped fists with him. "Try on your new uniform, so I can see how it fits."
"Eh?" Natsu looked at the bag. "Oh yeah. Right!" Natsu responded as he looked at his bag. Five minutes later, Natsu had undressed from his clothing and into his Demon Slayer uniform. "Wow! They gave me the perfect size!" Natsu was surprised that the Demon Slayer corps had given a uniform without taking measurements of him.
"It looks fantastic on you." Kyojuro said as he stared at Natsu in his Demon Slayer uniform.
"Oh, thanks!" Natsu stretched his arms a bit. "This is really exciting."
"What's making you really excited?" Kyojuro asked.
"I'm just thinking. The thought of me and big bro going on missions together, fighting demons side-by-side. We'll be the perfect tag team together." Natsu optimistically fantasized about himself and Kyojuro being surrounded by a group of demons big and small, then wiping them all out in the night. They were both dressed in their uniforms, their katanas were out and had courageous smiles on their faces. "This is going to be awesome!"
"Well, I'm glad you feel the same way." Kyojuro smiled at him.
Senjuro suddenly walked from another room to where Kyojuro and Natsu were chatting at the front door. "Hey, Kyojuro. Is that-" He stopped and gasped as when he saw Natsu make it in.
"Senjuro!" Natsu called.
Senjuro gasped. "Natsu, you're here! And you're dressed in your uniform, too!"
"Heh." Natsu chuckled as towards Senjuro. "What do you think?"
Senjuro paused for a second, then immediately ran towards Natsu with joy and happiness. They shared high fives together. "Congratulations."
"Thanks, bro! I'm an official Demon Slayer now. Which means that I can hunt down demons with big bro now!" Natsu and Senjuro shared high fives with each other.
"That's great. I'll start making dinner so we can celebrate." Senjuro said as he looked to his brothers, then proceeded to walk to the kitchen.
"Be careful not to cut yourself." Natsu said, as Senjuro left the hall.
"I will. Thanks." Senjuro responded as he left.
"Hey, Natsu. Let's talk more on the training ground." Kyojuro said, catching Natsu's attention.
"Oh. Right." Natsu followed Kyojuro to the Rengoku training grounds, where the sky was still blue.
"Now that we're here and alone, I want ask tell you something."
"What is it, big bro?"
Kyojuro moved closer and placed his hands on Natsu's shoulders. "Now that you're an official Demon Slayer, how would you like to be my Tsuguko?" Kyojuro asked.
Natsu's eyes widened and his teeth were closed. After hearing that question, Natsu's heart had stopped for a moment. Ever since he was little, his dream was to become a Hashira, like his father and brother. His heart started to beat faster and faster, as he was flowing with excitement. "Would I!" Natsu responded with joy.
"Excellent! That's exactly what I want to hear! Now as you know, being a Demon Slayer is not an easy job. Our goal as Demon Slayers are to hunt down and kill any and every demon that come across our path."
"Yes!" Natsu replied.
"And that's not all. These demons are being mutated or made by menace. A menace who has unleashed demons in Japan for a number of centuries. Right now, we Hashira are currently hunting this menace named is Muzan Kibutsuchi." Kyojuro explained.
"Muzan, huh?" Natsu paused.
"Right now, we still do not know of his whereabouts. But with you on our side, I believe we can locate and defeat him." Kyojuro was filled with confidents.
"Okay!"
"I'm going help you become the strongest Tsuguko there is, by training you." Kyojuro added.
"Alright! So when do we start?" Natsu asked.
Kyojuro suddenly walked to one side of the training grounds and picked up two wooden katanas meant for training. He then threw one of them towards Natsu from a long distance without warning, whom had caught it. "Right now." Kyojuro then took his swordsman stance in front of Natsu.
"Training starts right now." Kyojuro told Natsu.
Natsu smiled, then took a swordsman position as well. "I've gotten stronger during the Final Selections Exams." Natsu chuckled.
"I'm glad you did. And I am about to witness how strong you are, first hand. Don't hold back. Give me everything you got." Kyojuro encouraged.
"Right!"
Natsu and Kyojuro smiled and stood a yard or two from another on the Rengoku training grounds, as they were to spar with wooden katana. Everything around was quiet. No one was around. Nothing was making noises around them. A leaf had suddenly fell from a tree and slowly flew and towards the training grounds. Natsu and Kyojuro stared at one another, until the leaf had touched the training grounds.
Less than a second later, Natsu made the first move by dashing towards his brother and putting Kyojuro on the defensive. He made the first attack with the wooden katana. Kyojuro blocked the attack without the smile on his face wavering.
An hour and a half later.
The sky was turning from light blue to an orange-ish color. Kyojuro stood victorious and unfazed. Kyojuro did get some dirt on him, but didn't receive a scratch, as Natsu's body was stretched out on the ground defeated, with a few bruises on his body. Natsu was panting heavily on the ground as he had barely landed a blow on his brother.
"Well done, Natsu. You managed to last longer than last time. But you still have a long way to go." Kyojuro complimented Natsu.
"Aw man! Even after passing the Final Selections, I still can't land a blow on big brother!" Natsu pouted as he leaned his back upwards.
"Don't worry, Natsu. You still have time to get stronger. And one day, I'm sure you'll be able to surpass me." Kyojuro had walked towards Natsu.
Natsu sat his back up. "Really? You really think so?"
"I know so." Sparkle and glammer surrounded Kyojuro's face. He offered a hand to help Natsu up.
Natsu smiled back and felt a bit more of confidents. "Okay!" He gladly took Kyojuro's hand and stood up. Natsu the wiped the dirt of his Demon Slayer uniform.
Flashback
Kyojuro wore his Demon Slayer uniform with his Nichirin sword at his side. He roamed the halls of the Rengoku Residence until he had encountered his father, the Flame Pillare then, Shinjuro. Kyojuro was set to go out on his first mission until his father had opened up in conversation.
"You're heading off on your first mission, aren't you?" Shinjuro asked.
"Yes. I am, father." Kyojuro answered.
"What do you hope to accomplish?"
"I plan to save people and to become the next Hashira." Kyojuro said with optimism and without convictions.
"You can't do it." Shinjuro said plainly.
Kyojuro stopped for a moment.
"Both you and your brother Senjuro both lack talent. So, you shouldn't harbor impossible dreams. You can't take my place as Hashira."
Kyojuro remained silent.
As Shinuro was about to take a step and leave. "But... there is a chance that Natsu can."
"Huh?" Kyojuro was a little confused after Shinjuro mentioned Natsu.
"That boy has tremendous talent. But has yet to awaken his true potential." Shinjuro said before walking elsewhere. Kyojuro paused for a moment as he watched Shinjuro leave.
Kyojuro then walked outside within the training grounds. He spotted both Natsu and Senjuro practicing swings over and over with wooden katanas.
"Forty-seven! Forty-eight! Forty-nine! Fifty!" Natsu counted out loud. He did not break a sweat.
After fifty strokes, Senjuro collapsed on his knees and panted. He dropped the wooden katana as his hands hurt and bruised. "Huff... huff... huff..."
Natsu looked at his hands and kind of saw them being red. He walked over and patted Senjuro's back. "You did great, Senjuro. You're starting to catch up."
"Thanks, Natsu..." Senjuro panted less.
"Hm?" Natsu looked over at what Senjuro was staring and spotted Kyojuro. "Big bro!"
"Uh?" Senjuro spots Kyojuro as well.
"I see you two are working hard now." Kyojuro said as he approached them.
"Yeah we are. Senjuro and I managed to do fifty strokes without stopping." Natsu bragged.
"I'm kind of embarrassed..." Senjuro blushed.
"Don't be. You both managed to train really hard. That's outstanding!" Natsu laid a hand on Senjuro's shoulder.
Both Natsu and Senjuro gasped in happiness as they were just acknowledged by their older brother.
"I'm leaving for my first mission, now. So protect the house when I'm gone." Kyojuro grinned and placed his hands onto Natsu and Senjuro's heads.
"Okay!" Both Natsu and Senjuro easily replied.
"See ya!" Kyojuro then decided to run off, but was stopped by a cry.
"Big bro! I decided what I want to do with my life. I'm going to be a Demon Slayer, just like you. And then I'm going to become a Hashira, just like dad!" Natsu yelled.
"Yeah, what Natsu said! I want to be just like you, Kyojuro!" Senjuro shouted.
Hearing that almost made Kyojuro's eyes water. He then gave them both a thumbs up and a grin. A grin that Natsu would remember, until after the Final Selection Exams.
End Flashback
While fist bumping and grinning, Kyojuro could see the brightness within Natsu. 'Natsu... I truly believe that you could surpass me one day.'
"Dinner's ready!" Senjuro yelled as he ran towards the training grounds.
Both Natsu and Kyojuro then turned to and stared at Senjuro who had just appeared on the training grounds. Then rushed inside the residence as they were both hungry after sparring. The three young Rengoku lads had quickly sat at the family table, with a spread of cuisines on the table.
"Thank you for the food!" the boys prayed to the gods, then ate the food. The boys enjoyed the rest of the night.
Sixteen days had now passed since Natsu had passed the exams. Kyojuro kept his word by training Natsu to become the best Tsuguko he could be, physically and mentally. They both would continue practicing with katanas to be better swordsmen and practice Total Concentration Breathing at night. The only time Kyojuro wouldn't train Natsu is when he leaves to take missions as a Demon Slayer. Natsu would try and continue this routine on his own, until Kyojuro would return from his mission.