Kill Blue (キルアオ) is a Japanese manga series written and illustrated by Tadatoshi Fujimaki. It was serialized in Shueisha's Weekly Shōnen Jump magazine from April 2023 to September 2025, with its chapters collected in thirteen volumes. An anime television series adaptation produced by Cue (studio) premiered in April 2026.
Plot
Juzo Ogami is a 39-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 13. 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.
Characters
- Juzo Ogami (大狼 十三)
- A 39-year-old assassin who is aged back to 13 years old after being stung by a mysterious wasp during a mission. Initially not liking the idea of going back to middle school, he soon comes to enjoy it. His skill with a handgun has earned him the nickname "Demon's Left Hand".