Rengoku got his gear ready until he heard a voice.

???: Heading into battle?

He turned to Shinobu.

Rengoku: Ah, Kocho! We got new Intel about a demon, the Slayer who found it was defeated. We're losing Rank and filers now, we have to act!

Shinobu: Could it be a Twelve Kizuki?

Rengoku: Most likely. Maybe an Upper Rank.

Shinobu: It sounds like a difficult mission, but as long as you're going, Rengoku, we don't have to worry.

Rengoku: And you. What's the plan, taking in that head-butting kid? You mentioned recruiting more Tsuguko, but I doubt that's the reason.

Shinobu: You seem concerned. You don't think I'm going to gobble him up, do you?

Rengoku: Of course I don't! But what about L/n?

Shinobu: Well, I'll deal with him at a later date. When the drug I gave him wears off.

Rengoku: Then I shall be off!

Rengoku walked off with a hardy laugh.

Shinobu: Do be careful.

Inside the Butterfly Mansion, Zenitsu was making noise as usual.

Zenitsu: No! I can't possibly take any more of this!

Aoi: We go through this every day! Saying you're in bad shape is an understatement. Take your medicine this second!

Zenitsu grabbed his cup with teary eyes.

Aoi: Good grief. Tanjiro, this medicine is for you.

The little red butterfly girl gave Tanjiro a tea cup.

Girl: Here you go.

Tanjiro: Thank you very much.

Tanjiro took the cup and drank it instantly.

Zenitsu: Hey! I saw that medicine go down much easier! So then, it's different from mine! Favoritism! I call favoritism!

Tanjiro: Zenitsu, quiet down! This a hospital ward!

???: You all seem lively.

Tanjiro turned to the door to see Murata.

Tanjiro: Murata!

Murata: Hey!

Murata took a seat next to Tanjiro's bed.

Tanjiro: How have you been doing?

Murata: I came this close to being melted down. I survived somehow. I heard you guys got pretty banged up though.

Tanjiro: Yeah, it's gonna take time for us to bounce back.

Murata looked over to Inosuke.

Murata: What was it that happened to you, boar kid?

Inosuke didn't respond.

Murata: Is he sleeping or something?

Tanjiro: He went through a lot. You should just let him be.

Murata: But for him of all people to be silent.

Zenitsu: Tanjiro, who is this?

Tanjiro: He fought with us on Mt. Natagumo. He's a friend.

Murata: I'm Murata! Nice to meet you! What happened to your arms?

Zenitsu: My limbs shrunk down, because I was almost turned into a spider.

Aoi: And that's why you need to take this medicine!

Zenitsu: But it taste so gross! There's only so much grossness a person can take!

Aoi got right in his face.

Aoi: Don't come crying to me if your arms don't grow back to normal!

Zenitsu: So cruel! That's such a cruel thing to say!

Aoi: You don't know how good you have it! You realize if you take this medicine and get lots of sunlight, there'll be no lasting effects, don't you!?

Zenitsu: I can't do it!

Zenitsu jumped on to Tanjiro's bed.

Zenitsu: None of that changes the fact that stuff taste awful!

Murata's mood darkened.

Murata: Sounds like fun. Lucky you.

Tanjiro: What do you mean?

Murata: I was summoned to the Hashira Meeting to give my report on everything that related to the Mt. Natagumo incident. It felt like hell! Those Hashira are absolutely terrifying! They were all really furious about how the quality of the new Demon Slayers have gone downhill... because there were a number of us who neglected to follow orders during what happened up there. They were asking me things like who trained them anyway? What good was it asking a no rank like me into a meeting like that? But that's not even the worst bit. I accidentally ran my mouth in front of Master Y/n and he...

Zenitsu: Y/n what?

Murata: He started breaking my fingers!!! It took three Hashira to get him off of me and by that time he already broke nine of my fingers!

Tanjiro looked shocked, then Shinobu snook up behind Murata.

Murata: Him and the Hashira really terrify me!

Shinobu: Hello there.

Murata jumped out of the chair.

Murata: Lady... Lady Kocho!

Shinobu: Good day to you.

Murata bowed.

Murata: You as well! Goodbye!

Murata was about to run off, but he was stopped by Y/n who was holding his head down.

Murata: Oh, M-Master Y/n! Li-listen, I didn't mean what I said at the meeting and...

Y/n: The meeting? Oh. Look, I'm really sorry about everything. I was out of line and not on the right train of thought. Can you forgive me?

Murata: Wha- Oh, sure. I can.

Y/n: Good. You can leave now.

Murata ran out the door. Then Y/n walked over to a bed and fell face first into it.

Zenitsu: What did you do to him?! Because whatever it is, I like it.

Shinobu: See, Y/n misbehaved at the meeting, so I had to give him a special drug to calm him down. A side effect of this drug is great drowsiness.

Tanjiro: I hope it wasn't too hard to get him to take it.

Shinobu: Well...

She remembered Uzui and Shinazugawa holding Y/n down while he was screaming and kicking around.

Shinobu: It was a decent amount of effort. Now, the two of you. How are you feeling?

Tanjiro: I think we're a lot better now.

Shinobu: Well, if that's the case, let's have you start your Rehabilitation Training.

Tanjiro: Our Rehabilitation Training?

Shinobu: Yes!

Two weeks later.

Zenitsu was looking at himself in a hand mirror, seeing all the hair he grew back.

Zenitsu: So, Lady Kocho took Tanjiro and Inosuke to Rehabilitation Training to rebuild their strength. Which means...

He trailed off when Tanjiro and Inosuke came back looking all battered and rough.

Zenitsu: (Thinking: They're gonna come back looking like that.) Hey, welcome back, you two! How did it go today?

Tanjiro and Inosuke just ignored him and just went back to their beds.

Zenitsu: What's the matter? Did something happen?

Tanjiro: (weakly) Sorry.

Inosuke: (weakly) Don't mind us.

Zenitsu: Please tell me! I'm going to be the same boat as you starting tomorrow and I need to be mentally prepared!

???: What's with all the screaming?

They turned to see Y/n getting up and rubbing his eyes.

Tanjiro: Oh, Y/n! I'm sorry if we woke you.

Y/n looked at the three of them.

Y/n: Have I been out for long?

Tanjiro: Well, we know you don't usually sleep much, so we all decided to let you sleep in for an extra two-

Y/n: Hours?

Tanjiro:... Weeks.

Y/n: Hm.

Y/n got up and began stretching.

Y/n: I'm guessing you're going through Rehabilitation Training.

Zenitsu: Y/n, if you know about it, then please tell me!

Y/n: There's the full body massage, a cup game and a game of tag.

Zenitsu: Is that it?

Y/n: You'll see tomorrow.

The next day.

Tanjiro, Zenitsu and Inosuke walked into a big room with Aoi, Kanao and three little girls.

Aoi: All right, Zenitsu, since you'll be joining us starting today, I'll be explaining the training regimen again.

She pointed to the little girls that were standing over some futons.

Aoi: Those girls will get your bed ridden bodies limber again.

Inosuke laid down on his stomach as two of the little girls held his legs down while the third one pulled his arms. Inosuke was fighting back tears until they let go. Then Kanao sat on a table with lots of tea cups on it.

Aoi: Next, reflex training. These cups contain medicated water. The objective is to throw that water onto the other person, but there's a twist. Your opponent is able to block you from picking up your cup.

Tanjiro was Kanao's opponent.

Aoi: Go!

In the blink of an eye, Kanao threw a cup, splashing Tanjiro.

Aoi: Again! Go!

Tanjiro grabbed a cup, but Kanao blocked him and splashed him again.

Aoi: That's enough! Last, full body training. Or put simply, a game of tag. You will face myself, Aoi, and Kanao.

Zenitsu raised his hand.

Zenitsu: Excuse me. May I say something?

Aoi: Is there something not clear?

Zenitsu stood up.

Zenitsu: No, not that. You two, come with me.

Inosuke: Don't feel like it.

Zenitsu: I won't ask twice! So shut up and follow me!

Everyone was a little startled by his outburst and Zenitsu dragged Tanjiro and Inosuke outside. Not long after, Y/n walked in.

Y/n: Oh, hey. I heard shouting, what did I miss?

Aoi turned to him with a furious expression.

Y/n: What?

Aoi ran over to Y/n and slapped him square in the face.

Y/n: You know, I've been stabbed and mutilated, but that really hurt.

Aoi: You really think you're gonna do what you did and just walk around like nothing happened?! I should kill you right now!

Y/n: Then by all means, give it a shot.

Aoi punched Y/n in the chest, doing nothing.

Y/n: There. You hit me twice, now we're even.

Aoi: (growls) What are you even doing here?

Y/n: I came looking for my friends and Zenitsu.

Little girl: You just missed them.

They heard shouting outside.

Y/n: God. Sometimes I actually forget how loud Zenitsu can be.

He looked at the three little girls.

Y/n: I don't believe you were here when I left, little ones.

Red girl: We weren't. I'm Kiyo Terauchi.

Blue girl: My name's Sumi Nakahara.

Green girl: And I'm Naho Takada.

Y/n: Well, it's very nice to meet three. I'm sure you already know my name and some not so nice things about me.

Kiyo: Well, despite what we heard, it doesn't change the fact your going to be here.

Y/n: Well, if you're gonna be training with Zenitsu, I should tell you he gets especially annoying when girls like you all are involved.

Naho: Noted.

The three boys came back with Zenitsu looking the most happiest.

Zenitsu: I look forward to training with you!

Kiyo, Sumi and Naho started giving Zenitsu a body massage, but instead of crying like Inosuke, he was giggling.

Zenitsu: Keep going. This is fine.

Inosuke: I have underestimated him. I always fight back tears from the pain, but he's laughing from joy.

It then went to the cup game where Aoi was Zenitsu's opponent.

Aoi: I shall take you on.

Naho: And go!

Aoi grabbed a cup, but Zenitsu quickly stopped her and grabbed his own cup, but didn't splash her.

Zenitsu: I would never throw a drink in a girl's face.

The four girls looked like they were just about done. Then it went to full body training.

Kiyo: Now then, we will commence the full body training!

Zenitsu like a bolt of lightning grabbed Aoi.

Zenitsu: I win!

Aoi hit Zenitsu in the face, giving him a bruised check and black eye.

Zenitsu: I may have won the battle, but I lost the war!

Inosuke: I wanna win, too!

Inosuke splashed Aoi in the cup game.

Inosuke: All right!

Then he grabbed her by her ankles in full body training.

Inosuke: Take this!

Aoi: Let me down!

Y/n: My, my, dear Aoi. I didn't realize this was "Aoi gets owned day."

Aoi: YOU SHUT UP, BIRD BOY!!!

Tanjiro had a defeated look on his face and his clothes were soaked.

Tanjiro: I'm the only one on a losing streak now. So embarrassing!

Y/n: Don't lose hope, Tanjiro. You'll get better with time.

Zenitsu and Inosuke got splashed by Kanao.

Tanjiro: But no matter what I do, I can't beat Kanao. None of us can get to our cup first or block her from using her own.

Y/n: Well, she is a Tsuguko. You don't get that title for nothing.

Tanjiro: Hang on, you and her were both Tsugukos, right?

Y/n: Yeah.

Tanjiro: Then which one of you is stronger?

Y/n: That depends in which regards. I beat her in speed, but when we were younger, she beat me in terms of strength.

Tanjiro: What about now?

Y/n: I'm not quite sure.

Aoi: Well, if you want to know, why don't you do the training with her?

Y/n: I'm not a patient, I'm just here.

Aoi: Well, you can go then.

Y/n: Well, actually there is one problem. I have some aggression to let out, and beating on you might be my only therapy.

Y/n cracked his knuckles, but Tanjiro stepped between them.

Tanjiro: Uh, hey, Y/n, I saw some really nice birds outside. Want to see them with me?

Y/n: Sure, that sounds great.

Tanjiro: (Monologing: For the next five days, I continue to lose to Kanao. So did Inosuke and Zenitsu. We can so much as lay a finger on a strand of her hair. Then one day, the other two stopped coming. Meanwhile, Y/n wasn't hurt like us, so he could still do missions. But a Hashira had to be supervising him.)

Y/n got back to the Mansion with Iguro.

Y/n: Well, this is where I get off. You can fuck off now, snake.

Iguro: I wish the demon ripped your throat out.

Iguro walked off and Y/n entered the mansion to see Tanjiro walking out of the training room.

Y/n: Hey, Tanjiro. Did you just get back from training?

Tanjiro: Yeah. You from a mission?

Y/n: Yep.

They started to walk together.

Tanjiro: (Thinking: Why can't I beat her? What gives her an edge over me? First of all, her reflexes are way faster. I'd probably still lose at full strength. Her scent is totally different. It's similar to the scents of Y/n and the Hashira. Also, her eyes! Her eyes are different!)

Y/n: Tanjiro!

Tanjiro: Huh?

Y/n: Those three are trying to talk to you.

He looked to the side to see the butterfly triplets.

Sumi: Tanjiro, are you all right? We've been calling to you over and over.

Tanjiro: Oh, I'm sorry. What is it?

Kiyo: This is for you!

She gave him a towel.

Tanjiro: Thank you! This helps! You're all so kind!

The three gave very bright smiles.

Kiyo: Um, I wanted to ask if you keep the Total Concentration Breathing state all of the time?

Tanjiro: Huh?

Kiyo: Do you use the Total Concentration Breathing technique non-stop? Morning, noon and while you're asleep?

Tanjiro: Can't say I do. Never thought to. Can someone pull that off?

Kiyo: Yes! We're told that being able to do such a thing makes all the difference in the whole wide world!

Tanjiro: Even just using that technique for a short period of time really takes a toll, but I should do it around the clock, huh?

Naho: Some people have already been able to master it.

Sumi: All of the Hashira, Kanao and we heard Y/n can even do it!

All three: We hope you can do it!

Tanjiro: Wait, Y/n, you can use this technique?!

Y/n: Yes. It's called "Total Concentration Breathing: Constant." As the name states, it's where we make Total Concentration Breathing a state we constantly live in.

Tanjiro: How come you've never told me about it before?!

Y/n: Well, I didn't think you were ready for it. But if we're going to be fighting the Twelve Kizuki, I think now is a good time to learn it. Get some rest, I'll start your training tomorrow.

Tanjiro: All right! Thank you, all of you!

Tanjiro ran into his room.

Kiyo: I can see that you two are very good friends.

Y/n: We are.

???: Yo-ho!

Shinobu came out of nowhere.

Y/n: Oh, great, you.

Shinobu: It's good to see you awake, Y/n. Could you please come with me? I would like to talk to you about something.

Y/n: Okay.

They walk off until they got to a room with only one bed.

Shinobu: Please sit down.

Y/n sat down on the bed and Shinobu pulled out a water lily.

Shinobu: I got you this flower to say I hope you are well.

She then dropped the flower onto the ground and smashed it with her foot, still keeping her smile.

Shinobu: I am now taking your flower away to show disapproval for your actions.

Y/n: Meh, I never really liked flowers that much anyways.

Shinobu: Everyone is so pissed at you.

Y/n: Can't say I blame them.

Shinobu: We understand you being forced to become half demon, but not when you stabbed us.

Y/n: I didn't stab all of you. I left Mitsuri and Kanae alone. Besides, don't act like you care that I left. You seemed to have replaced me already.

Shinobu: Replaced you?

Y/n: With that new guy. Tokyo, I think his name was.

Shinobu: Oh, you mean Tokito. Well, he isn't as much of a brute as you were, that's for sure.

Y/n: I have a feeling this was more of a way for you to annoy me than give me a lecture.

Shinobu: Well, what else would I do with my favorite little brat?

Y/n: Just leave.

Shinobu: Fine. But since you're not a patient anymore, we can't allow you to use the patient rooms.

Y/n: So what, you just going to make me sleep outside?

Shinobu: No, you'll just be using this room from now on.

Y/n: What's so special about this one?

Shinobu: You really don't remember? This was the room you stayed in when you were younger.

She left the room, leaving Y/n to look down on the floor.

The next morning.

Y/n was sitting on the porch with Tanjiro standing in front of him.

Y/n: Okay, a good way to start this off is to see where your limit is. So, use Total Concentration Breathing for as long as you can.

Tanjiro: Right.

Tanjiro began to use the Total Concentration Breathing technique.

Y/n: Looking good so far.

Tanjiro looked like he was really straining to keep it up, but then he dropped to his hands and knees. Y/n quickly rushed to help him.

Y/n: Tanjiro, you okay?!

Tanjiro: I can't do it! If I try to do it longer than usual, it makes me feel like I'm gonna die! It's too painful! My lungs hurt! My ears are ringing so hard, it feels like they're gonna burst! Wait, did they?!

Y/n: Calm down. Your ears are fine. Now that we know what your limit is, we can train to break it. We'll start by taking in more steady breaths.

Tanjiro: Okay! I'll keep moving forward!

Y/n got back on the porch and watch Tanjiro do his steady Total Concentration Breathing.

Y/n: I know you three are there, so there's no point hiding.

The three butterfly triplets came from around the corner.

Kiyo: Sorry, we just wanted to see Tanjiro's progress.

Y/n: As long as you don't get in the way, you may watch.

Sumi: Why don't we get you both some rice balls?

Y/n: Do whatever you want.

Naho: Oh, we have something that might help.

They brought rice balls and tea for the boys and also some gourds.

Tanjiro: Blow into these gourds?

Y/n: Oh, the gourds. How could I forget?

Kiyo: Lady Kocho trained Miss Kanao. And whenever she did, she had her blow into gourds like these.

Y/n: I did this training, too.

Tanjiro: Really? That's a neat training technique.

He bit into a rice ball.

Tanjiro: So, do you make a sound or something?

Kiyo: Oh, no. She blew into it and made the gourd go all ka-boom.

Tanjiro: Wow! Ka-boom? Wait, this thing? Explode?

Tanjiro tapped it.

Tanjiro: Something this hard?

Kiyo: That's right! Not to mention, this is a special kind of gourd, so it's even harder than normal ones.

Y/n: Here, let me show you.

Y/n took a quick sip of his tea and grabbed a gourd, then he took a deep breath a blew into it, causing it to explode.

Y/n: There. Easy enough. Though, I warn you that the gourds will get bigger as you progress. Hey, what size can Kanao break?

The three pulled out a gourd that was bigger than them.

Kiyo: This on right here!

Tanjiro: It's huge! I'll give it a shot!

15 days later.

Y/n was standing near the door to Tanjiro's room. Waiting for Tanjiro to come by, then he did.

Y/n: I'm quite impressed with how far you've come, Tanjiro.

Tanjiro looked at Y/n.

Y/n: What?

Tanjiro: Y/n, did you know a woman named Kanae Kocho?

Y/n bit his lip at that name.

Y/n: I did, but how did you?

Tanjiro: Miss Kocho told me that she had anger towards demons because of her older sister's death.

Y/n: Can't say I don't understand the feeling.

Tanjiro: Miss Kocho said that Kanae had some final words for you.

Y/n: I wouldn't be surprised if they were to tell me that she hated me.

Tanjiro: She said, "I'm sorry, I couldn't save you."

Those words hit something in Y/n.

Tanjiro: I'm gonna go to bed.

Y/n: Me too.

They both walked into their rooms. When Y/n got there, he dropped to his knees and began to break down into tears.
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Preview.

Tanjiro: Sniff, sniff! Did something nice happen to you just now?

Shinobu: Yes! I've developed a valuable medicine.

Tanjiro: Sniff, sniff! Are you angry?

Shinobu: Yes! Someone keeps stealing the candy from the shelves.

Tanjiro: Sniff, sniff! You're also feeling sad.

Shinobu: There's a disturbance nearby.

Tanjiro: Now, it's time for a Taisho-era secret! Since Aoi has been training under Shinobu, I hear is now able to make the simpler medicines.

Shinobu: Nothing escape your nose, Tanjiro! That's amazing!

Tanjiro: Sniff, sniff! It seems like...

Shinobu: I must say, I enjoy talking to you.

Tanjiro: (light blush) Thank you so much! Next, Episode 25, "Tsuguko, Kanao Tsuyuri."

To Be Continued.