Synopsis
J is a notorious assassin known throughout the criminal underworld for being untouchable. While walking down the street, he unexpectedly bumps into a solitary elementary school student named Megumi. This collision triggers a bizarre event that causes them to swap bodies. Consequently, J must navigate the daily life of the young girl Megumi, while Megumi is thrust into the dangerous world of the hitman J. The story follows their chaotic and humorous struggles as they attempt to live each other's lives.