The next morning, Rengouku was getting ready to leave for his next mission, as he put his sword away. 

Even though the Fire Hashira was ready, he was still thinking about the events that happened the day before. 

"Nezuko really is something else, isn't she?" He thought, "I still can't honestly believe she would actually head-bump Samei like that though. I guess that I had a lot to learn from that girl and her demon brother of hers." 

A voice interrupts his thoughts as Kocho asks him, "You're already been assigned to a mission already? That was quick. " 

He turns as he saw the Insect Hashira. 

"Oh, is that you, Kocho? Yeah, I had been assigned to a mission by the Master . It appears that there was a demon and the Demon Slayers that confronted , had been killed off . We can't just stand there and do nothing. We are losing ranks if this keeps up. You know that better than anyone." Rengouku said to her. 

"Is it possible that the demon you are referring to might be a Twelve Kizuki?" Kocho asks. 

"Possibly. It might be one of the upper ranks of the Twelve Kizuki, but we still have to be sure if it is ." He replied. 

Kocho smiled at the Fire Hashira, "That seems like a difficult mission, but I know that you are capable of doing it, Rengouku. I'm not worried , just be careful on your mission , all right?"

"I will , and while we're at it, what you going to do with Nezuko who is at your place right now?" Rengouku asks curiously of what the Insect Hashira going to do with the Demon Slayer. 

"Don't worry, I'll think of something. You should get going." She said, as Rengouku laughs, "I guess you're right. I'm off!" He said, leaving her . 

Zen was not capable of taking the medicine again. 

"No! I'm not taking it again! " He said, as the girl sighs , "Zenitisu, you must take it, seriously! You're the one who was poisoned by the Demon Spider and you're severely injured from that fight remember? 

You must take it in order to be better and regain your arms and legs again."

Nezuko seems to be anguished at her friend's complaints, as the girl looked at her directly. 

"Nezuko, your medicine is right over here." She said to her as her helper gives it to her as she said, "Thanks so much. " 

She was about to drink her medicine as Zen said, "Hey, how come her medicine is different than mine?!? That is so wrong!" 

She tries to calm him down, "Zen, com'on! This is a infirmy! Please stop complaining already and man up!" 

A voice said, as he said, "Well, I take it that you're doing well, Nezuko! I'm actually relieve that you're ok! I was actually worried about you!" 

She turns to see a familiar face as she exclaimed, "Wow! Murata! It's you! " 

Murata smiles at her as he waves at her as she was relieved to see he was doing well too, from being able to escape safety from the mountain at Mt. Natagumo. 

She said, "I haven't seen you since Mt. Natagumo. I was worried about you escaping from the mountain. Are you feeling ok since then?" 

The Demon Slayer nodded of how concerned she was for him as he replied, "Yeah, I was almost getting melted away at a precise moment, but I managed to be saved by one of the Hashiras, thankfully. 

When I arrived here, I heard about you guys being all banged up from Mt. Natagumo. I guess that having that Lower Moon Five Kizuki really had given you a tough time huh? " 

"Yeah, I guess that you could say that. It's going to be some time for us to rest before we can ever get into missions again." She explains to him. 

"Well, I guess that boar kid, his thoart was damaged right? What's his story?" Murata asks Nezuko.

She sweats, "Well, Inosuke went through a lot, so if you really want to please him, just let him be for the moment." 

The Demon Slayers were silent for a moment, then Zen was curious of seeing Nezuko interacting to someone he doesn't know. 

He asks, "Hey, I don't mean to interrupt , but um, Nezuko, who is this?" 

Nezuko realizes that he never met Murata before , as she said, "Oh, right, you guys haven't met yet. This is my friend, Murata. He was fighting alongside with Inosuke and me back at Mt. Natagumo. He's also a Demon Slayer like us. " 

He said, "I'm Murata! It's a pleasure to meet you, even though, you're all banged up." 

Murata seems to be disappointed as Nezuko asks, "Hey, what's wrong?" 

"Well, to be honest, I was summoned on the Hashira Meeting last night to give my report on Mt. Natagumo... The Hashiras were so terrifying! Not to mention how they reacted of how many Demon Slayers were murdered there..." 

She said, "I guess that was really hard, giving a report in front of the Hashiras. I wished I've gone to it. It seems interesting." 

"Hey!" Someone said behind him as Murata gaps, "Lady Kocho! You startle me! I should be leaving you! " He ran as he closes the door behind him in a hurry to not be seen her again. 

"Well, that was something. How was recovery coming along?" Kocho asks. 

Nezuko replied back to her, "Well, I think we're getting better somehow." 

"Well, how about we do some rehab training?" She suggested. 

Nezuko was confused by her words as she blinks, "Rehab training? What's that about?" 

It was three weeks since they arrived at the Butterfly House as Zen thought, "It's truly amazing. Nezuko , Inosuke and I begin our rehab training by Lady Kocho. Although, her voice is truly unique, so enchanting. 

I wonder how their rehab training went." 

As to his shock of seeing Nezuko and Inosuke been worned out by their rehab, like they were dead zombies! 

He said, "Welcome back , you guys! How did it go with Lady Kocho's training?"

They collapse in their beds, being so tired, as Nezuko replied, "Sorry, Zen. " 

"We're so tired. Don't mind us." Inosuke added. 

Zen said, "C'mon! Tell me! I'm going to be with you guys tomorrow! " 

The next day, Zentisu joined with his friends to rehab. 

"Since Zentisu is joining us today, I'm going to explain the process. You'll be joined with my other assistances , as you regain your body muscles . 

Next, rehab reflexs training. Lady Kocho would be helping you with that with using the cups of tea . Your main goal is to prevent the other from putting the water into you. " 

Nezuko was trying her reflex training, but she fails again and again, due to she was not quick of reaching the cup in time . 

"Lastly, it's full -body training. You will have to do combat with Lady Kocho, Aoi and me. " 

"Well, it seems to be complex. Um, not to brag, but can I speak with both Nezuko and Insure for a moment?" 

He dragged both of the Demon Slayers as Nezuko said, "Zen! What's this about?"

"You get to be with those girls all day , and you are being tired about it?!? You're both Demon Slayers aren't you?!? " He said, as Nezuko sweats as Inosuke said, "C'mon, try to make sense, Zenitisu. " 

He punched him as Nezuko gasps of what he has done, as she said, "Inosuke! You all right? Zen, I'm a girl, remember? It's kind of a difference when we're together." 

Days passed as Zen and Inosuke was training at their best as Nezuko was amazed of her friends' determination , despite she was the only one lacking on the training. 

"Zen and Inosuke . They're training so hard to get better. Me? I'm lacking , considering I'm sore and also getting soaked a lot. 

Kocho is something else entirely . I couldn't be able to catch up with her. Her ability to move was so amazing. Even though she was tough to beat, they both gave up of training entirely. " 

"Zen, Inosuke! Come back!" She said, but both boys didn't listen. Nezuko knew that she has to be stronger than Kocho. 

She turns to her as she said, "Please, train me, Lady Kocho. Don't stop." 

They trained as to Nezuko's limit as Kocho said, "You should head back. It's enough for today." 

"Thanks for training with me, Kocho. I appreciate it." She said to the Insect Hashira as Nezuko thought to herself, "There has to be a way to defeat her. But how can I do that? Why can't I beat Kocho?"

The girls who was assisting Kocho touches her to get her attention, "Ms. Nezuko? You all right?"

"Oh, sorry! I didn't hear you that time. What's up?" She asks the girls. 

"Here's a towel. Hey, I have a suggestion. Have you ever considering of using Total Contraction Breathing on the clock?" She asks. 

Nezuko was surprised by the suggestion, "Using my Total Contraction Breathing on the clock? What you mean by that?" 

She said, "I mean, by using it constantly, Day and Night, even if you're sleeping." 

She blinks in shock, "I've never done it that way before. Is that even possible I can manage that?"

"Yes, you can. We were told that using that technique really sharpens your mind." The girl replied. 

Nezuko was overwhelmed by the information, "It really took a toll on me, I never consider doing it!" 

"Some people mastered it completely, ms. Nezuko. All the Hashiras have mastered it, which includes Lady Kocho!" 

Nezuko realized that it was the perfect opportunity to finally beat Kocho at her own game as she said, "All right! I'm going to give it a try! Thanks you guys! " 

The morning after , She turns to Inosuke, "C'mon, Inosuke, isn't time you begin your rehab training? Sulking in bed wouldn't do a thing. Zen, can you please help me get him out of bed and begin rehab with me?"

Zen said, trying to make an excuse , "I'm going to make tea. See ya, Nezuko!" 

She sighs that knowing that he wasn't helping at all. 

She begins to do Total Contraction Breathing. "Total Contraction Breathing. Morning. Noon . Night. Even when I'm asleep, I should master it constantly. " But the pain was horribly bad on her. 

"Awe man! I can't! I can't do it!! If I constantly do Total Contraction Breathing in this state, I'll die!"

Nezuko shook her head , trying to control herself, "Never mind that. I think I should start with the basics that Sensei taught me.  Breathing is all about lungs. If my lungs aren't strong enough, that means it is weak than it used to be. " 

The girls was watching her. "She's really working hard. I'm glad she's doing what she can to make herself heal again. " 

"Yeah, I bet she's hungry after all her training. Let's treat her with some rice balls to regain her strength. " The other girl said. 

"I agree . Also..." The third girl said. 

The girls were together as Nezuko was listening. "Also, Lady Kocho trained with these gourds with her Breathing." 

"Oh, really? That's cool I guess. " Nezuko said, as she munches a rice ball. "What type of sound does that make?"

"Sound? No, silly. She actually blew it to pieces." 

Nezuko was shocked. "Wait, you're serious?" She pounds on the hard gourd. "She blew this all on her own?!?" 

"Yep. That gourd is special one, compared to normal ones. " 

"No way!! Kocho really can blow something that hard is so amazing! It's so unbelievable that she's a Hashira!" Nezuko thought . 

The girl said, "The gourds get bigger as you progress. The one that Lady Kocho can blow is this one!" 

The girls showed her the biggest gourd she ever seen as she said, "That is so freaking huge! I'll do my best!" 

The next following days, she constantly doing all the training skills she had learnt and she was able to regain her stamina . 

At night, she was on the rooftop, mediating. "Mediation. It helps with the Breathing. Sensei. Mr. Hagenezuka. " 

She imagines how mad that Mr. Hagenezuka must've felt of hearing of how she broke the sword he had made for her, "How dare of you breaking my sword!!!" 

She sweats of how mad he must be, "Please forgive me, Mr. Hagenzuka. They were able to reforge my sword, I am truly sorry for the trouble I've cause. "

She shook her head to focus. "Concentrate! Concentrate! " 

A voice said, "Nezuko. Nezuko! " 

She turns around to see Kocho staring at her. "I see you're working hard. Even though your friends aren't with you. 

Aren't you lonely up here?"

Nezuko said, "It's all right, Kocho. Once I've master the technique, I will teach them . It's best to start training before teaching others, right? You're a Hashira after all. " 

Kocho said, "You really care about them, don't you? You have a beautiful soul, Nezuko." 

She blushed at the Insect Hashira of her comment. "You really think so? So, what brings you up here all by yourself?"

"Well, Tanjiro has been acknowledged , and you three have been severely injured. Also.. I want to ask you something. " 

"What is it?" Nezuko asks. 

"Can I .. Can I entrust you to my dream too?" She asks , which startled the Demon Slayer as she didn't expect that question from her. 

"A dream? Kocho, I don't get it. Why you asking me this?" Nezuko asks. 

"Well, I know it seems like an impossible dream, but my dream is to be friends with the Demons. I'm sure you can accomplish that no matter what." 

Nezuko sniffs her as she asks, "Kocho , you're feeling angry about something, aren't you? I can smell an angry feeling coming from you, even though you're smiling behind your emotions. " 

She was amazed by Nezuko's strong sense of smell. "Oh, you can tell , just by smelling me? That's so uncanny that someone noticed right away. 

You got me. I'm angry . It's because it's ever since my sister was slaughtered by a demon. Every time I see the tears of someone losing someone they loved to a demon, every time I hear the cries of despair, the anger , it boils inside me and continues to swell to this day. " 

Nezuko listened in amazement of how she was confessing her feelings. 

"Since Tanjiro is a demon who never devoured a human, with their own eyes, and memorize their presence. 

Out of respect of the Master's wishes, I don't think anyone would lay a hand on him. " 

Nezuko was curious , as she said, "My big sister was kind-hearted , just like you, Nezuko. She had smphany for the demons as well. Even with her dying breath, she was caring for the demon's well-being. 

I wasn't like her at all. How do I feel the same way you and my sister do? How do I feel sorry for them? But that is what my sister felt until the very end, and I must carry on what she had done for me. " 

Nezuko felt bad for her, as she said, "Kocho. It's not your fault that your sister died. " 

"I know. But now, I feel exhausted. Demons lie . They think that humans really are the source of good food they desired." 

She stood up, "So, Nezuko. Don't ever give up. Please do what you can . Find a way to protect Tanjiro no matter what it takes." 

Nezuko was silent for a moment as she realized of how much Kocho was helping her in her own special way. She left her to let her focus on the technique . 

"Thanks a lot, Kocho. You helped me a lot." She whispered. She thought about her deceased family. 

"Mom. Takeo. Hanako. Rokuta. I know you're watching over me. I'm giving it my all. I'm going to change Tanjiro back into a human, no matter what it takes! "