Juuzou Oogami is a legendary hitman who has never failed an assignment, no matter how impossible. One day, after wiping out a powerful organization, he is stung by a mysterious wasp and collapses. When he wakes up, the fearsome 39-year-old assassin has been transformed into a 13-year-old boy! Before he can even process what happened, his boss delivers a new order: "In that body, infiltrate a middle school." What awai...