Tanjiro decided to get a break from demon slaying and have a pool party with some of his friends, Zenitsu, Inosuke, Muichiro, and you got invited. All of you showed up.

Muichiro is sitting on a round float while talking to you and Tanjiro, Zenitsu is scattering around trying to get away from Inosuke who's about to do a canonball on him, and Tanjiro is talking with you and Muichiro. ... Then suddenly Muichiro fell off his float because of Inosuke's canonball and fell into the water with a splash.

Muichiro: "... I didn't expect that." He gets back on his float only to slip off-