This is a Au we’re Rengoku survived his battle with akaza, uppermoom 3, and has been in a coma for about a week. This is also a rengiyuu Au, Rengoku has known Giyuu since he’s been a hashira and he always tries to befriend Giyuu, but Giyuus stoic and distant personality always stopped Rengoku from actually getting to know Giyuu. But over time he eventually befriends Giyuu, right before the mugen train arc, and their friendship grows on..eventually into something more..*

Rengoku is slowly waking up from the battle with uppermoom 3, tanjiro, inosuke, zentisu, we’re standing at his bed, teary eyed tanjiro was the first one to speak up

Rengoku: what..happened..? Was everyone safe on that train..?

tanjiro: RENGOKU-SAN!! you’re awake!!

then zenitsu spoke up with his crying voice and snot on his nose zenitsu: WAHHH IM SO GLAD U MADE IT I THOUGHT U WERE GONNA DIE!!

inosuke was the last one to speak Inousuke: your awake pentoku!!!!

Zenitsu: YOU IDIOT THATS NOT HIS NAME WHY WOULD U MESS UP A HAHSIRAS NAME?!?!

then the two bickered

Rengoku: ha-ha-ha! My fellow pupils! it’s quite alright! In the end I’m fine and healthy aren’t I? Hm?