Kill Blue

Juzo Ogami spent decades as the world's most efficient assassin, never failing a single contract until a mysterious wasp sting during a mission in 2023 rewrote his biology. He woke up inside the body of Juzo Ogami, a thirteen-year-old middle school student with no memory of his violent past but retaining all his lethal skills and adult memories. This bizarre rebirth forces him to navigate the absurdities of adolescence while hiding his true identity from classmates and teachers alike.

His former boss orders him to enroll at a local school to protect the boss's daughter, who happens to be a student there. The narrative balances high-stakes assassination plots with deadpan comedy derived from the contrast between Ogami's world-weary professionalism and the trivial dramas of teenage life. He must dodge enemies from his past who have tracked him down or are hunting for the source of his transformation while dealing with cram school, classroom politics, crushes, and sports clubs.

Written and illustrated by Tadatoshi Fujimaki, the series ran in Weekly Shōnen Jump from April 17, 2023, to September 1, 2025, collecting into thirteen tankōbon volumes released between September 4, 2023, and February 4, 2026. The English version is published by Viz Media under their Shonen Jump imprint. An anime adaptation produced by Studio Cue premiered on April 11, 2026, directed by Hiro Kaburagi, and concluded its first season on June 27, 2026. [edit]