"Senjuro! I'm home!" Natsu Rengoku shouted after arriving in the Rengoku Residence which he stay in. "I'm back from my mission!"

Suddenly, Senjuro had ran from another room to greet Natsu. "Natsu! I'm glad you made it back. How did your missions g-" Senjuro gasped as he spotted someone behind Natsu. He saw a boarhide lurking behind Natsu.

"Get over here!" Inousuke yelled as he leaped over Natsu's head like a frog and charged at Senjuro like a boar.

"AAAAAAAAH!" Senjuro screamed as Inosuke tackled him and pinned him to the floor.

"I got you now, Kurojuro!" Inosuke yelled as he placed a knee on Senjuro's back and pulled on his left arm.

"W-who's Kurojuro and what do you want?" Senjuro teared up as Inosuke placed him under a submission.

"For someone who's a Hashira, you're not as strong as you're cracked up to be." Inosuke said as he kept torturing Senjuro.

"N-no! I'm not a Hashira!" Senjuro yelled.

"Inosuke, stop! Stop!" Natsu yelled as he pulled Inosuke off Senjuro and placed him in a full neson, once again. "That's not Kyojuro!"

"What is it now, Hatsu?" Inosuke looked at Natsu.

"My name is Natsu-and that's not my older brother, Kyojuro. This is my other brother, Senjuro Rengoku." Natsu explained, before letting him go.

"Senjuro?"

"That's right." Natsu said before letting go of Inosuke.

"Senjuro... Senjuro... Senjuro!" Inosuke screamed as steam blew from his boarhide snout.

"Y-yes?"

"For someone with a high and mighty name, you sure are a very weak Demon Slayer." Inosuke said.

"I'm not a Demon Slayer!" Senjuro yelled in a weak manner.

"Are you good, Senjuro?" Natsu asked Senjuro.

"N-Natsu! Who in the world is this guy?" Senjuro questioned Natsu as he felt intimidated by Inosuke's appearance.

"Hm?" Natsu looked at Inosuke, then looked back at Senjuro. "Oh, yeah. Sorry I forgot to tell you. Senjuro, this is Inosuke Hashibara. We took the Final Selection Exams, together and we managed to stop the demons." Natsu introduced Senjuro to Inosuke.

'Final Selection Exams... Mount Natagumo... Hashibara?' Senjuro had thought.

"Hey, Natsu, can you come a bit closer?" Senjuro politely asked.

"Oh, sure." Natsu easily agreed.

"Mm-hmm." Natsu nodded.

"How do you write that last part? Hashibara?" Senjuro whispered.

"Oh, that? I'll tell you a secret. He can't write or read." Natsu whispered back.

"Really?" Senjuro then giggled after hearing Natsu's comment.

Inosuke saw Senjuro giggling with Natsu and instantly found it to be irritating. "Hey, you! What are you laughing at!"

Senjuro flinched and gasped toward Inosuke. "N-nothing!" Senjuro instantly answered.

"You better not be laughing at me, or I'll-"

"Hoho! I hope I didn't miss anything."

Natsu and Senjuro gasped together when they heard an older masculine voice that they easily recognized. 'That voice!' They looked toward the entrance to see their older brother and mentor, Kyojuro Rengoku standing in front of the open doors. He was smiling as usual and crossing his arms.

"Big brother!" Both Natsu and Senjuro chanted.

"You've returned from your mission." Senjuro said as he gazed at Kyojuro.

"Who the heck are you?" Inosuke interrogated Kyojuro.

"I see that you've made a friend, Natsu." Kyojuro said as he looked at Inosuke.

"Yes, I have." Natsu stood between Inosuke and Kyojuro. "Bro, this is Inosuke Hashibara. We passed the Final Selections and slayed demons together."

"Heh. Funny last name." Kyojuro commented.

"And Inosuke, this is my older bro, Kyojuro. One of the Hashira I was telling you about. We'll be training under with him to get stronger." Natsu introduced Inosuke to Kyojuro.

"Wait-training? Stronger?" Inosuke paused and gave it some thought in his mind. Then a glowing firefly appeared floating over his head. Steam blew through his boarhide snout as he got excited to train. "Aw, yeah! I'm ready to do some training!" Inosuke jumped up and down, then pulled out his dual Nichirin Swords.

"Eek!" Senjuro squealed as he stared at Inosuke's dual blades.

Kyojuro raised a hand forward, causing everyone to pause. "Before we begin our training... I have a question I must ask Natsu." Kyojuro turned and looked at Natsu.

"Anything, bro!" Natsu responded with a smile on his face.

"Did you know that Tanjiro's younger sister is a demon?" Kyojuro asked with a normal smile on his face.

'Eh...' Natsu's face then turned blue out of fear when Kyojuro asked him that question. His heart sunk and his normal smile dropped into an embarrassing smile. 'That's right. I forgot bro went to meet Tanjiro at the summit!' Natsu then thought of Nezuko Kamado of when he met her. 'I hope both of them are okay.' Natsu then embarrasingly gulped in front of Kyojuro.

Kyojuro showed no reaction, but a smile on his face.

'Be calm and tell the truth!' Natsu hesitated for ten seconds. Then, he suddenly found courage to talk to Kyojuro by looking him straight into the eyes, then raised his right hand high in the air. "YES! I DID KNOW THAT TANJIRO'S SISTER IS A DEMON! NEZUKO KAMADO IS INNOCENT! SHE'S HELPED US FIGHT OTHER DEMONS WHILE WE WERE ON THAT MOUNTAIN! I BELIEVE SHE CAN HELP US FIGHT AGAINST MUZAN KIBUTSUJI AND THE TWELVE KIZUKI! I HAPPILY ACCEPT HER INTO THE DEMON SLAYER CORP!" Kyojuro shouted.

Kyijuro paused for a moment after hearing Natsu's speech. "I see..." Kyojuro then put on a big smile on his face. "That's the spirit! If you believe that Nezuko can be part of the Demon Slayer Corps. then I will put my faith in her, too!"

Natsu happily gasped after hearing that Kyojuro accepted Nezuko.

"And I almost killed her!" Inosuke yelled and raised his left hand in the air.

Natsu grunted after hearing Inosuke's small speech. "Inosuke! What are you doing?"

"I was about to kill her outside of a mansion, but that blonde-headed idiot named Genichu protected him. Then another idiot called Manjirou broke few of my ribs and headbutted me." Inosuke said Tanjiro and Zenitsu's names wrong.

"Stop, Inosuke! That's no way to talk about Zenitsu and Tanjiro!" Natsu argued with Inosuke.

"What's it to you! You weren't there when it happened!" Inosuke yelled back.

"Haha!" Kyojuro's laugh broke up the small argument. "It seems you two will be fine Demon Slayers, one day." Kyojuro commented.

"Bro?" Natsu muttered.

"Say..." Kyojuro then drew out his Nichirin Sword. "How would you both like to accompany me in my next mission?"

Both Natsu and Inosuke stared at Kyojuro with dotted eyes, then glowing fireflies appeared over their heads. Then they both happily gasped. "Do we!" They both yelled out of happiness. Inosuke used his flexibility to roll over backwards and Natsu stood upside down on one of his hands. They were both happy for a solid minute.

'I'm finally going to slay some powerful demons for sure!' Inosuke thought.

'This will be my first mission ever fighting alongside with bro! I've been waiting for this day for years!' Natsu thought.

'I'm very excited!' Both Kyojuro and Natsu thought as they felt very optimistic.

Kyojuro watched both Inosuke and Natsu feel and act very happy, until he saw a person enter the residence. "Oh. It seems we have a visitor." Kyojuro pointed at a person standing behind Natsu.

"Huh?" Inosuke stood back on his feet to see a woman, then took a step back.

"Eek!" Senjuro squealed again.

"Eh?" Natsu then stood back on his feet as well to hear Senjuro squeal, then felt a dark presence. He looked behind himself to see an irritated Swordsmith named Chiyo standing behind him. Natsu could see a visible red cloud of aura surrounding Chiyo's body. He paused for a moment, then decided to smile in front of Chiyo. "Hi, miss Chiyo. How are you-"

Chiyo raised her hand in front of Natsu's face. "My baby. Where is it?"

"Eh?"

"Where is my baby?"

Natsu stared at Chiyo for a few seconds, then he gasped as he thought of something.

Short Flashback

"If you do break, snap, chip or even crack my baby... there's going to be SEVERE consequences." Chiyo said in a dark edgy voice.

End Flashback

"Oh! You mean, the Nichirin Sword you made for me." Natsu then removed his Nichirin Sword from his waist and presented it to Chiyo. "Here."

"Gimme that!" Chiyo swiped Natsu's Nichirin Sword from him. She opened the sheath to see if Natsu's Nichirin Sword had been damaged in any way. It took an entire minute for Chiyo to inspect Natsu's Nichirin Sword.

Natsu stared at Chiyo with a weird smile and small black dotted eyes. "Uh..."

Kyojuro continued smiling.

Senjuro looked a bit worried.

Inosuke just stared.

"Oh! Looks like it hasn't been cracked or chipped, yet."

'Yet?' Natsu thought.

Chiyo sighed in a bit of relief. "Thank goodness." Chiyo gave Natsu back his Nichirin Sword.

"Um, so... what brings you here, miss Chiyo?"

"I heard a rumor that a Demon Slayer had broken their Nichirin Sword on Mount Natagumo. So, I came here to see if it was you or not." Chiyo said.

Natsu then thought back on the night of Mount Natagumo. He remembered seeing Tanjro and his broken Nichirin Sword after he killed Rui. 'She must be talking about Tanjiro.' Natsu stopped thinking back. "Well, I guess it's a good thing that I didn't break it then." he gave Chiyo and embarrassing chuckle.

"Yes. It is a good thing. Because I know that I could trust you with one of my babies. When I heard the news, I got very suspicious. I got on my hands and knees and prayed to the gods that you didn't destroy my baby." Chiyo also said.

Natsu stared at her with a weird expression.

"No need to worry, ma'am! Your baby is in excellent care of my younger brother." Kyojuro smiled at Chiyo as he defended Natsu.

Natsu noticed Kyojuro's hand on Natsu's right shoulder. "That's right!"

"Good." Chiyo nodded. Six seconds later, Chiyo walked to the front door of the Rengoku Residence, opened the front door and was preparing to leave. "Oh, before I go, I one last message to give you, Natsu." Chiyo looked solely at Natsu.

"Yes?"

"I'm keeping a close eye on you from now on."

"Uh?" Natsu didn't follow Chiyo.

"I know that you are fighting demons for a living... but whether you're fighting demons or humans... that doesn't excuse you from having my baby destroyed. Remember that." Chiyo said.

"Y-yes ma'am!" Natsu replied as he placed his arms to his side.

"Good boy." Chiyo closed the door behind her and left the Rengoku Residence.

There was complete silence for two whole minutes. Even Inosuke was quiet.

"Who wants to train?" Kyojuro asked randomly.

"I do!" Both Natsu and Inosuke answered.

Two Minutes Later

Natsu and Inosuke followed Kyojuro outside and were led to the Rengoku Residence training ground by him. All three Demon Slayers wielded wooden katanas. Inosuke wielded a wooden katana in each hand, while Natsu and Kyojuro only wielded one. Kyojuro sat and watched as Natsu and Inosuke were about to begin sparring.

"Remember, Natsu! Inosuke! You're both pretending that I'm a strong demon! Dont hold back in the slightest!" Kyojuro yelled as he had taken his swordsman stance.

"Right!" Natsu chanted.

"I'm going in!" Inosuke instantly charged toward Kyojuro with two wooden katanas in his possession, then jumped a few dozen feet in the air.

Natsu inhaled some air, then charged toward Kyojuro whom was on the defense.

"Hyaaah!" Inosuke cried as he dived toward Kyojuro head first like a bullet.

Kyojuro stood still and remained in his fighting stance until they were in close range.