Kny swap au

Hashiras are upper moons and the upper moons are Hashiras

Hakuji(firework Hashira): stretching and taking a break from training

Douma(ice Hashira): Hakuji! smiling Muzan just informed me that we had a mission together soon!

Hakuji rolls his eyes

Ume(beauty Hashira): Complaining to her brother gyutaro

Gyutaro(blood Hashira): Listening to Ume ramble

Michukatsu(moon Hashira): watching everyone from the other side of the courtyard