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, with its chapters collected in ten volumes as of June 2025.

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.

Characters

;Juzo Ogami
:The main protagonist. He is a 40-year old assassin who is aged back to 12-years old after being stung by a mysterious wasp during a mission. Initially, he didn't like the idea of going back to middle school, but he soon came to enjoy it. His skill with a handgun has earned him the nickname "Demon's Left Hand".
;Noren Mitsuoka
:The main heroine. She is a middle school student and the daughter of Mitsuoka Pharmaceuticals founder. She is constantly hit on by other students, causing her to initially hate men, before befriending Ogami. She helps out her Uncle at his Ramen Shop, and wishes to takeover it when he retires.
;Kotatsu Nekota
:Ogami's partner. Although not nearly as experienced as Ogami, he is skilled with technology, and has more skill in cooking and house care. He created the pair of glasses that Ogami wears that acts as a camera and radio for him.

Publication

Written and illustrated by Tadatoshi Fujimaki, the series began serialization in Shueisha's ''Weekly Shōnen Jump'' magazine on April 17, 2023. As of June 2025, the series' individual chapters have been collected into ten volumes.

Viz Media and ''Manga Plus'' are publishing the series in English simultaneously with its Japanese release. Viz Media began releasing the volumes digitally in July 2024.

Volumes

Chapters not yet in ''tankōbon'' format

These chapters have yet to be published in a volume.
*89.
*90.
*91.
*92.
*93.
*94.
*95.
*96.
*97.
*98.
*99.
*100.
*101. Sir, Yes Sir!
*102.
*103.
*104.
*105.
*106.
*107.

Reception

The series was ranked seventh in the Nationwide Bookstore Employees' Recommended Comics of 2024 list. The series ranked tenth in the print category at the tenth Next Manga Awards in 2024.

Kaylie Fielden of ''Screen Rant'' felt the plot was unique among other hitman manga and praised the beginning chapters. Robbie Pleasant of ''Multiversity Comics'' praised the artwork and characters. Regarding the story, Pleasant felt that it has some worrying elements but nonetheless handled them well. Kara Dennison of ''Otaku USA'' described the series as "''Case Closed'' with added violence".

References

Also See

*Kuroko's Basketball, another series written by Tadatoshi Fujimaki
* Robot × LaserBeam, another series written by Tadatoshi Fujimaki

External links

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{{Weekly Shōnen Jump - 2020–2029

Action anime and manga
Comedy anime and manga
Fiction about rapid human age change
Anime and manga set in schools
Shōnen manga
Shueisha manga
Viz Media manga