Waking up in the world of Demon Slayer, he even became the "scum senior brother" Kaigaku! Since he's become Kaigaku, he absolutely has to change everything! He can't control what's already been changed, but he will definitely save everyone he can change! He will ensure that his older brother, who died before dawn, survives unharmed! Kaigaku: "I didn't have a choice before, but now I want to be a good person." (Infinite flow, current world: Demon Slayer.) (Next world: Fate/Zero)