The joke is that Asahi has zero power in a fantasy world built for overpowered protagonists, and the show actually commits to that being funny instead of tragic. His sister Maya demolishes everything with one hit, and instead of resenting her, he becomes the person keeping her grounded, which is the opposite of every isekai you've watched. The comedy lands because it's not trying to be clever about subversion, it's just watching a useless guy figure out his actual value while his sister casually warps the entire power dynamic of the genre.
Asahi gets his wish when he's suddenly transported to a fantasy world straight out of the games and novels he loves. The problem: he arrives powerless, with no special abilities to speak of. Just as panic sets in, his older sister Maya appears at his side, and she's won the cosmic lottery. She possesses absurdly overpowered skills that let her obliterate any threat in a single strike. What could be a devastating disadvantage becomes the setup for something entirely different. With Maya's godlike strength protecting him at every turn, Asahi gets to experience the adventure he always wanted, except filtered through his sister's smothering protection and devastating combat power. Their dynamic becomes the heart of the story: Asahi trying to carve out his own path while Maya handles every obstacle before it even becomes a problem. The series balances genuine fantasy worldbuilding with comedy born from their sibling relationship and the sheer absurdity of having an unstoppable force watching your back. Expect heartfelt moments alongside laugh-out-loud situations where Maya's casual strength solves everything.