Kill Blue

is a Japanese manga series written and illustrated by Tadatoshi Fujimaki. It began serialization in Shueisha's Weekly Shōnen Jump magazine in April 2023; as of September 2023, a single volume has been released. Plot Juzo Ogami is a 40-year-old who works for the Z.O.O. assassin syndicate as their prized hitman. During a job taking out criminals working with the genetic manipulation company Mitsuoka Pharmaceuticals, Ogami is stung by a wasp that modifies his DNA, regressing his age to that of when he was 12. Unable to resume work as a hitman due to his stature, the head of Z.O.O. gives Ogami another assignment while they work on an antidote: attend a middle school the head's daughter is applying to and judge if it is safe. Ogami, due to having no formal education, turns out to love middle school, and must balance his time as a student and an assassin. He must also deal with Noren Mitsuoka - the heiress of Mitsuoka Pharmaceuticals, who may be the key to figuring out how to age Ogami back to normal. Publication Written and illustrated by Tadatoshi Fujimaki, the series began serialization in Shueisha's Weekly Shōnen Jump magazine on April 17, 2023. As of September 2023, the series' individual chapters have been collected into a single volume. Viz Media and Manga Plus are publishing the series in English simultaneously with its Japanese release.