Asahi Ikusaba is a high schooler who got lost and ended up stumbling into another world. He has inherent knowledge of video games and fantasy worlds, so he had tried to use that to fully enjoy the new world he found himself in. The problem is... he's pathetically weak and has no "cheat ability" to make life easy for himself. But then who appears before him? His sister, Maya Ikusaba, who has this world's ultimate cheat ability and a huge brother complex. Can he use his excessively overprotective sister's divine protection as a weapon? And so, Asahi's life in another world continues...