No. 6

NO.6［ナンバー・シックス］ (No.6)

9.0(1)

OtakuDen

7.5(217,070)

MAL Score

Ranked #1993

Popularity #576

Action
Drama
Mystery
Sci-Fi
Psychological
Survival

Episodes: 11
Duration: 23 min per ep
Aired: Jul 8, 2011 to Sep 16, 2011
Status: Finished Airing

Synopsis

Years after a devastating world war, humanity retreats into six carefully controlled city-states, with No. 6 presented as a calm, orderly utopia. Shion, raised among its privileged elite, has his certainty shaken when he crosses paths with Nezumi, a mysterious boy fleeing capture from beyond the city’s walls. Though Nezumi is a wanted fugitive from the barren wasteland outside, Shion shelters him for a single night—an act of compassion that costs Shion and his mother their elite status and exposes him to the city’s hidden cruelties.

Much later, Shion and Nezumi meet again, their lives now shaped by that first encounter. Together, the former prodigy and the runaway are drawn into a dangerous search for the truth, peeling back the layers of No. 6 and the secrets sustaining its fragile perfection.

Otaku Consensus

No.6 is remembered as a striking but compressed Bones dystopia: Kenji Nagasaki’s direction, the tense Shion-Nezumi pairing, and the strong opening stretch give it more charge than many 11-episode sci-fi adaptations. Its reputation is held back by the same complaint across fan and critic reactions: the adaptation moves too quickly for its conspiracy, villain motivation, tonal shifts, and source-material complexity to fully land.

Why You Should Watch

If you want compact dystopian sci-fi driven by intimacy, class anger, and institutional paranoia rather than police-procedural lore dumps, No.6 is the 11-episode pressure cooker to pick. It scratches a related itch to Ergo Proxy for false-utopia suspicion and Banana Fish for volatile male-codependent tension, but with Bones' clean TV-action cuts and a shoujo-inflected emotional lens. Its best material is the friction between Shion's moral absolutism and Nezumi's survivalist pragmatism, a dynamic that makes even quiet rooms feel like contested territory. Watch it for a swift, mood-heavy conspiracy drama with an Aimer ending theme; skip it if you need encyclopedic world-building or a fully unpacked villain architecture.

Key Characters

N
Nezumi(VA: Yoshimasa Hosoya)
Nezumi is the series' pressure point: charismatic, guarded, and frequently debated by fans because his tenderness and cruelty can sit in the same scene without resolving neatly.
S
Shion(VA: Yuki Kaji)
Shion stands out less as a standard dystopian rebel than as a moral idealist whose compassion becomes both his strength and his most dangerous liability.

What Makes It Stand Out

1
Studio Bones gives the series a polished early-2010s TV look, with reviewers consistently singling out the action animation as sharper than the relatively small number of fight scenes might suggest.
2
The anime runs only 11 episodes, a structural choice that makes it unusually easy to marathon but also central to its criticism: multiple reviews identify the middle stretch, final escalation, and villain groundwork as casualties of compression.
3
The adaptation’s appeal hinges on the Shion-Nezumi relationship rather than conventional genre mechanics, which is why audience reactions split sharply between viewers wanting a fuller BL romance and viewers valuing the restrained, ambiguous emotional bond.
4
Keiichi Suzuki’s score, LAMA’s opening theme, and Aimer’s ending theme give the show a distinct music identity, though critics were divided on the background music’s fit with the tone.
5
Its tag profile is unusually hybrid for a short sci-fi series: AniList marks it heavily for Conspiracy, Class Struggle, Cyberpunk, Survival, Shoujo, and even Classic Literature influences.

Fun Facts & Trivia

Fun fact 1: No.6 is based on work by novelist Atsuko Asano, with original character designs credited to toi8 and anime character designs handled by Satoshi Ishino.
Fun fact 2: The anime was directed by Kenji Nagasaki, who later became widely associated with My Hero Academia, making No.6 an earlier showcase of his ability to handle heightened emotion inside genre material.
Fun fact 3: Aimer performed the ending theme; No.6 aired in 2011, the same year her major-label debut single 'Rokutousei no Yoru' was released.
Fun fact 4: Yasuomi Umetsu is credited for key animation, a notable production detail given his reputation for highly polished character motion and stylized action animation.
Fun fact 5: Despite its divisive reception, the series has broad visibility: it holds a 7.55 MAL score from 216,942 votes, a MAL popularity rank of #573, and 3,233 AniList favourites.