Under Ninja

Name: Under Ninja
Genre: Action
Released: 2023-10-06

アンダーニンジャ

6.9(27,404)

MAL Score

Ranked #5536

Popularity #2795

Action
School

Episodes: 12
Duration: 24 min per ep
Aired: Oct 6, 2023 to Dec 22, 2023
Status: Finished Airing

Synopsis

Ninjas, once thought to have vanished, resurface in post–Pacific War Japan and quietly embed themselves throughout society. Rumored to number around 200,000, they operate from the shadows, carrying out covert missions while infiltrating both government bodies and private organizations.

Kurou Kumogakure is one of them—an unmotivated 17-year-old who drifts through life in a shabby apartment and is dismissed as a deadbeat, even accused of swiping beer from a neighbor. That listless image masks something far more dangerous, and it’s tested when Kurou receives orders to go undercover at a nearby high school—an assignment that quickly proves more complicated than it first appears.

Otaku Consensus

Under Ninja landed as a cult-leaning 2023 outlier rather than a broad crowd-pleaser: Satoshi Kuwabara’s Tezuka Productions adaptation earns its strongest praise for deadpan absurdism, grubby urban style, and sudden, nasty fight choreography that treats ninja fantasy like bureaucratic espionage. Keiichirou Oochi’s fractured, time-skipping series composition is also the main sticking point; viewers who enjoy density call it bold, while mixed reviews repeatedly cite confusion, hard-to-track conspiracy threads, and a season-ending cliffhanger.

Why You Should Watch

Watch Under Ninja if you want ninja anime stripped of heroic gloss: less grand destiny, more cigarette-stained apartments, institutional paranoia, casual perversity, and violence delivered with a straight face. It scratches a similar itch to Dorohedoro’s ugly-funny absurdism and Durarara!!’s urban web of hidden factions, but with a colder, more deadpan sense of humor. The appeal is not clean power-scaling or emotional speeches; it is the pleasure of watching a modern shadow-war unfold through awkward conversations, sudden brutality, and deliberately off-balance chronology. Viewers who like their action shows weird, seinen, and slightly hostile to easy explanation will get far more from it than anyone looking for a conventional school-battle anime.

Key Characters

K
Kurou Kumogakure(VA: Taito Ban)
Kurou is memorable because his bored, almost vacant affect turns him into an anti-charismatic lead whose deadpan presence makes the series’ perversion, violence, and spy comedy feel even stranger.

What Makes It Stand Out

1
The series uses an achronological structure significant enough to be one of its defining viewer tags, with time skips and delayed context shaping how the conspiracy is understood rather than simply decorating the story.
2
Its comedy is unusually dry for an action anime: user reactions repeatedly single out dark, weird, and perverted humor that plays against gruesome violence instead of softening it.
3
Tezuka Productions pairs a grounded urban look with character designs by Nobuteru Yuuki, sub-character designs by Chihiro Ueno, and prop design by Natsumi Yamada, giving the show a more lived-in texture than a glossy ninja spectacle.
4
The school element is not treated as a simple classroom-comedy framework; it sits beside espionage, military, and conspiracy tags, making the setting feel like one more institution being infiltrated.
5
The action has a reputation for sharp, strange ninja choreography, while the show’s partial use of CGI is notable enough to appear among its audience tags rather than disappearing into the background.

Fun Facts & Trivia

Fun fact 1: Under Ninja is based on an original work by Kengo Hanazawa, whose authorship helps explain the show’s seinen sensibility and comfort with grotesque, socially awkward comedy.
Fun fact 2: The anime aired as a 12-episode Fall 2023 series from October 6 to December 22, 2023, with Satoshi Kuwabara directing and Keiichirou Oochi handling series composition.
Fun fact 3: Its reception numbers reflect its divisive cult profile: it holds a 6.88/10 on MyAnimeList from 27,350 votes, a MAL rank of #5524, and an AniList score of 66/100 with 396 favorites.
Fun fact 4: The franchise also received a 2025 live-action film directed by Yuichi Fukuda, and web coverage of that version singled out Kento Yamazaki’s natural performance.
Fun fact 5: Editing is credited to Wataru Uchida, an especially relevant role here because many viewer complaints and compliments focus on the show’s abrupt time jumps and dense episode-to-episode information flow.