Kenji Seto is a sage who was killed by a monster and reincarnated in the modern world. In a world with no monsters, there aren't many reasons to use magic. But then Kenji's current little sister started to get a little rebellious... Now he's got plenty of chances, and plenty of targets! From his cheeky little sister to the school slut, Kenji's going to make good use of his old skills in this new life...