Inosuke and Zenitsu were watching Tanjiro play an intense round of the cup game with Kanao.

Zenitsu: Incredible...

Inosuke: Look at them go!

They kept going until Kanao was able to grab a cup.

Aoi: That's it!

Tanjiro: (sigh) You sure are fast, Kanao.

Kanao just looked at him.

Aoi: Your score is now ten wins and ten losses.

Tanjiro: I'm still up for more. Let's go for a run.

He looked at Zenitsu and Inosuke

Tanjiro: Want to join me?

Zenitsu: You mean while doing Total Concentration, Constant?

Tanjiro: Yeah.

He hit Zenitsu in the chest, but Zenitsu still stood.

Zenitsu: I gotta keep this up?

Inosuke opened his shirt.

Inosuke: Do me next!

Zenitsu hit him in the chest repeatedly.

Zenitsu: How's this?

Inosuke: That's nothing!

Zenitsu: you're more brawn than brain!

Tanjiro: Let's go!

Elsewhere.

Y/n was sitting on a tree.

Y/n: (Narrating: Meanwhile. As my friends were still training, I couldn't shake the feeling there was something off.)

Y/n got an image of a young man with feminine facial features being dropped in an alleyway with vains visible on his face and drolling. Y/n quickly shook his head and his hawk landed on his shoulder.

Hataki: Is something the matter, Master Y/n?

Y/n: Yeah, let's get going.

Y/n jumped down and moved along the path.

Back at the Butterfly Mansion.

The three boys were awoken by Tanjiro's crow.

Crow: The casualties of the Mugen Train. More than 40 are missing as it currently stands. You are to join Kyojuro Rengoku and Y/n L/n on site. Head west at once, at once!

In the morning.

Tanjiro was walking through the halls with his usual smile.

Tanjiro: All right, time to go!

Tanjiro saw a shadow of someone around the corner.

Tanjiro: (Thinking: Someone's coming.)

The person bumped into Tanjiro.

Tanjiro: (Thinking: He was really adamant about bumping into me. Wait, this guy...)

He turned his head to see it was Genya, but he got taller and more muscular, and he wore a purple tunic over a dark green Demon Slayer uniform.

Tanjiro: (Thinking: Was he at Final Selection?)

Tanjiro remembered when Y/n broke Genya's fingers.

Tanjiro: (Thinking: He bulked up a lot in such a short time. There's something else... his scent...) It's been awhile! Glad to see you're doing well!

Genya completely ignored him.

Genya: (Thinking: That dumb ass should know better than to act buddy-buddy with me after what his dumb ass friend did.)

Flashback.

Genya was walking through the Mansion until he saw Y/n cleaning his blade.

Genya: Hey, you!

Y/n: Huh?

Genya: So, we meet again.

Y/n cocked his head.

Y/n: Uh, do I know you?

Genya: What was that?!

Y/n: Hmm. Oh, yeah. You're that bum ass who's fingers I broke. Ah, good times. Your name is Genya, right?

Genya: Don't first name me, punk ass birdbrain!

Y/n: You really are Sanemi's brother.

Y/n jumped back on his feet and returned Eleatara to its Sia.

Y/n: I'd love to fight you, but I've got more important things to deal with then you.

Y/n walked away.

End flashback.

Tanjiro went to Aoi to say goodbye.

Aoi: Oh, really? You're heading out now? It was only for a short time, but I'm glad we got to spend it together. Good luck out there. You take care now!

Tanjiro: Thanks for everything! You looked after us even though you were busy yourself! And now, we can get back in the battle!

Aoi turned to get back to the laundry.

Aoi: No need to thank me. It was by chance I got through Final Selection. And after that, I was too cowardly to even step foot into battle. Not like Y/n.

Tanjiro: You seem to have been really close to him. And I could tell that even when you showed you were mad, you were the saddest when he left.

Aoi: (sigh) Y/n wasn't just another patient here for me. When he got here, who do you think took care him? Who do you think was there for him? Who do you think loved him?!

Tanjiro: Loved him?

Aoi: He was like the brother I never had. And for him to leave me and make me wonder if I meant nothing to him.

Flashback.

A young Aoi was minding her own business when she saw Y/n walking through the hall with his head down.

Aoi: Y/n, you're back.

Y/n stopped for a second and looked at Aoi, showing his pale skin and the bags under his eyes.

Aoi: You don't look very good! You need some sleep!

Y/n looked down.

Y/n: I will never sleep again.

Aoi: If it's one of those nights again, I'll come sleep with you.

Y/n: You know, you are probably the most annoying person I've ever met.

Aoi: What?

Y/n suddenly appeared behind Aoi.

Y/n: Don't come after me.

Y/n chopped her in the back of the neck and she fell to the ground.

End flashback.

Tanjiro: Y/n would never do that!

Aoi: He did, but there was also something else. Something I thought I just imagined.

Flashback.

Aoi reached for Y/n.

Aoi: (weakly) Y/n...

Y/n turned back to her with tears in his eyes.

Y/n: Forgive me.

End flashback.

Aoi: I thought I had just imagined it. What about you? Do you think it was real?

Tanjiro: I know it was. I know Y/n felt truly sorry for what he did. Didn't you two make up?

Aoi: Yeah, we did.

Flashback.

Y/n was sitting on the porch with Aoi folding laundry.

Aoi: So, you're heading out.

Y/n: Yep. Might be gone for awhile, so that'll be your chance to celebrate.

Y/n was about to get up and leave.

Aoi: Y/n, wait.

Y/n stopped and looked at Aoi who held out his repaired mask.

Aoi: Good luck in battle.

Y/n took the mask.

Y/n: My mask? But...

Aoi: Tanjiro told me how much it meant to you, so I thought as a way to accept your apology I should fix it for you.

Y/n looked at his mask and put it on.

Y/n: Thank you.

Aoi: It's no problem.

Y/n gave her a really quick hug which surprised her before Y/n broke it and left.

End flashback.

Tanjiro: Well, you are a part of Y/n and he will carry you into battle with. As will I. If I get hurt, I hope you'll look after me again!

Tanjiro left for Aoi to look at him with a silent awe. Then he went to Kanao to tell her goodbye.

Tanjiro: There you are! Hey, Kanao! We're heading out now. Thanks for everything!

They stood in awkward silence for a bit until Kanao pulled out her coin.

Tanjiro: What's that?

Kanao flipped the coin and it landed on tails.

Kanao: All I did was follow the teacher's orders. So there's no need for you to thank me. Farewell.

Tanjiro gave a big smile.

Tanjiro: (Thinking: She actually talk to me!) What was that you just flipped?

Kanao: Bye, for now.

Tanjiro: Money?

Tanjiro sat next to her.

Tanjiro: It says heads and tails, huh? Why did you flip it?

Kanao: Goodbye.

Tanjiro: You sure made that thing spin!

Kanao: I flip this to decide things that weren't ordered. Just now, I decided weather to speak to you or not. Don't speak was heads, and do speak was tails. And tails is what it landed on. Farewell.

Tanjiro: Why don't you choose for yourself? Which do you want to do?

Kanao: It doesn't matter. Nothing matters to me, so I can't decide for myself.

Tanjiro: I don't think there's anything in this world that doesn't matter. I guess... the voice in your heart is just really tiny. Following orders is important to an extent, but...

Tanjiro came up with something.

Tanjiro: Hey, can I borrow that?

Kanao: Sure.

Kanao gave Tanjiro her coin.

Tanjiro: Thank you.

Tanjiro ran out into the yard with it.

Tanjiro: Ok! We're going to use this to decide!

Kanao: Decided?

Tanjiro: whether you'll listen to your own heart from this point on!

Tanjiro flipped the coin really high into the air.

Tanjiro: Ah! I flipped it way too high! Heads! Let's make it heads! If it comes up as heads, you're going to follow your heart!

A strong gust of wind blew the coin around, making Tanjiro struggle on where it was going to land, but he did catch it.

Tanjiro: See that, Kanao?! I got it! Are you ready?

Kanao: (Thinking: Which will it be? His back was blocking it, so I couldn't see which way it fell.)

Tanjiro showed it landed on heads.

Tanjiro: It came up as heads! Here you go!

Kanao held out her hand, expecting to get her coin back, but Tanjiro grabbed her hand with both his.

Tanjiro: Remember! It's the heart that drives people. So, it can grow as strong as you need it to! All right! See you later!

Tanjiro ran off.

Kanao: How? How did it come up heads?

Tanjiro turned back to her.

Kanao: (Thinking: I saw his hand when he flipped it. I'm sure he didn't cheat. But still...)

Tanjiro: Just by chance. Although, if it were tails, I was gonna keep tossing it until it finally came up as heads!

Tanjiro gave a kind smile and Kanao felt something in her.

Tanjiro: Take care of yourself!

Tanjiro left. Kanao looked at the coin in her hand and held it close to her chest.

Outside.

Tanjiro, Zenitsu and Inosuke were all presented with gaint gourds that they blew into and destroyed.

Triplets: Great job, everyone!

The triplets offered them a basket of rice balls.

Sumi: For you!

Tanjiro: Thanks, girls!

Inosuke was attempting to eat all of them and Zenitsu was trying to stop him. Tanjiro saw Tomioka around the corner and ran over to him.

Tanjiro: Tomioka!

Tomioka: Heading into battle now?

Tanjiro: Yes, sir!

Tomioka: I heard you've mastered Total Concentration, Constant.

Tanjiro: I have!

Tomioka: You should keep at it.

Tanjiro: Yes, sir. Tomioka... About Nezuko and Y/n... Thank you very much. The fact you put your life on the line, I had no idea. I don't know how to ever repay you.

Tomioka: You can thank me by doing your best work. Our mission is to kill demons, that is all. Oh, and be sure to look after Y/n. Got it?

Tomioka vanished.

Tanjiro: Got it!

Later.

The sun was setting and trio made it to a train station where Inosuke was freaking out about the train.

Inosuke: Hey, wait a damn minute. Wh-what the- What the hell is this creature?!

It was a blanket train with the word, "Mugen" at the front.

Inosuke: Wait, could it be? I've heard of such a being! The master and ruler of this land! It's such an intimidating size! There's no mistaking it! It looks like it's asleep, but don't let that fool you!

Zenitsu: It's a train. You never seen one?

Inosuke: Shush! Or you'll wake it! I'll lead the charge to take it down!

Tanjiro: Inosuke, stop! This might be the guardian spirit of this land. So we shouldn't be attacking it carelessly.

Zenitsu: Uh, I said it's a train. You've never seen one either? A vehicle for transportation.

???: Guys?

They turned to see Y/n with a bunch of bento boxes.

Tanjiro: Y/n!

Y/n: I see you got called to help with this Mission as well.

Zenitsu: Y/n, please tell me you know what this is.

Y/n: It's a train. What else would it be?

Tanjiro: This is what the crow was talking about?

Y/n: Yes, this is the Mugen Train. Considering you and Inosuke grew up on mountains, I'm not too surprised you don't know what it is.

Inosuke: What are you holding?

Y/n: These are bento boxes. As for why I have them, that's a bit of a long story that will have to wait. We need to get on board.

Y/n got on the train.

Y/n: What's taking them so long?

Y/n saw them getting chased by some policeman.

Y/n: Shit.

Y/n moved cars until he got to the car with Rengoku and sat with him.

Rengoku: What took so long, Young Y/n?!

Y/n: Saw my friends and a friend of theirs and thought I'd say hi. Now, I don't know about you, but I'm feeling a bit peckish.

Y/n took out a bento and so did Rengoku.

Y/n/Rengoku: (pray) Thank you, for the food.

Y/n adjusted his mask to eat with Rengoku.

The End of Season 1.

(A/n: Hey, guys. I just wanted to say thanks for your support on this story. It was really fun writing it. I hope you all do good. And I'll see you again in the Mugen Train arc.)