Kill Blue

• Ja Kanji — キルアオ • Ja Romaji — Kiru Ao • Genre — * Action • Comedy

• Type — manga • Author — Tadatoshi Fujimaki • Publisher — Shueisha • Imprint — Jump Comics • Magazine — Weekly Shōnen Jump • First — April 17, 2023 • Last — September 1, 2025 • Volumes — 13

• Type — tv series • Director — * Hiro Kaburagi (animation supervisor) • Yasunori Ide (animation director) • Writer — Hiro Kaburagi • Music — Ryo Konishi • Studio — Cue (studio) • Licensee — Remow • Network — TXN (TV Tokyo) • First — April 11, 2026 • Episodes — 12

• Portal — yes Kill Blue 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 tankōbon volumes. An anime television series adaptation produced by Cue (studio) premiered aired from April to June 2026. A second season has been announced.

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.

• Juzo Ogami: • 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". • 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. • Eri Wanibuchi: • Ogami's ex-wife who is the head of Z.O.O.'s science department. • Noren Mitsuoka: • 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 take it over when he retires. • Chisato Shiraishi: • A third-year middle school student who is the head of the Home Economics Club. She is affectionately referred to as "Capo". • Shin Kohazame: • An assassin associated with Yugang, a Chinese organization, who is Ogami and Noren's classmate. Due to his tendency of being nervous, he often uses a pacifier to calm himself down. • Tenma Tendo: • A second-year middle school student who is a three-way athlete known as "The Triple Threat". Due to his versatility and abilities, he is a member of "Unicorn", an elite group of students. • Kazuma Rindou: • A Black-Rank assassin associated with JARDIN. He is skilled in hypnotism. • Eiji Rindou: • A Black-Rank assassin associated with JARDIN who is Kazuma's younger brother. He has tremendous physical strength and is a skilled golfer. • Mai Otohime: • A first-year student who is a member of Unicorn due to her specializing in marine sports. Known as "The Mermaid Queen", she has a split personality that switches when she sleeps. One personality is meek and gentle, while the other is energetic and prideful. She has a crush of Ogami, unaware that he is really a middle-aged man.

Written and illustrated by Tadatoshi Fujimaki, Kill Blue was serialized in Shueisha's Weekly Shōnen Jump magazine from April 17, 2023, to September 1, 2025. The series' individual chapters have been collected into thirteen tankōbon volumes, released from September 4, 2023, to December 4, 2025. Viz Media and Manga Plus simultaneously published the series in English with its Japanese release. Viz Media began releasing the volumes digitally in Summer 2024.

An anime television series adaptation was announced on September 1, 2025, the same day as the final chapter of the manga. It was produced by Cue (studio) and directed by Yasunori Ide, with supervision and series composition handled by Hiro Kaburagi, characters designed by Miho Daidōji, and music composed by Ryo Konishi. The series aired from April 11 to June 27, 2026, on TV Tokyo and its affiliates. The opening theme song is "ATTITUDE" performed by Aespa, while the ending theme song is "KILL SHOT" performed by Riize. Remow licensed the series for simultaneous streaming worldwide on several platforms. An English dub by Bang Zoom! Entertainment premiered on the same day. Following the airing of the final episode of the first season, a second season was announced.