Knights of Sidonia stands out for its cold, survival-focused science fiction, unconventional animation, and a narrative that constantly subverts heroic expectations. Its themes of isolation, evolving power systems, and humanity’s fragility in the face of extinction give it a tone few anime fully replicate.
The following 15 underrated anime series explore similar ideas—whether through existential sci-fi, morally ambiguous character arcs, or experimental storytelling—and deserve far more attention than they typically receive.
1. Fafner in the Azure (2004)
- Streaming: Crunchyroll (region-dependent)
- Episodes: 25 (plus sequels)
- MAL Rating: ~7.3
- Studio: Xebec
- Notable Staff: Tow Ubukata (series composition)
- Awards: Japan Media Arts Festival selection
Overview:
A group of isolated youths pilot biomechanical weapons to defend humanity from unknowable alien beings. The cost of survival steadily erodes their humanity.
Similarities to Sidonia:
Both explore child soldiers, biological mecha, existential threats, and the emotional toll of endless warfare.
2. Bokurano (2007)
- Streaming: HiDive
- Episodes: 24
- MAL Rating: ~7.4
- Studio: Gonzo
- Notable Staff: Hiroyuki Morita (director)
Overview:
Fifteen children sign a contract to pilot a giant robot—only to learn each battle costs a pilot’s life.
Similarities to Sidonia:
Bleak tone, subversion of mecha tropes, and a relentless focus on sacrifice over heroism.
3. Infinite Ryvius (1999)
- Streaming: Currently unavailable (physical media)
- Episodes: 26
- MAL Rating: ~7.4
- Studio: Sunrise
- Notable Staff: Gorō Taniguchi
Overview:
A stranded space station full of students must form a new society to survive.
Similarities to Sidonia:
Closed-system survival, political power struggles, and psychological breakdown under isolation.
4. PlanetES (2003)
- Streaming: Crunchyroll
- Episodes: 26
- MAL Rating: ~8.3
- Studio: Sunrise
- Awards: Seiun Award nominee
Overview:
Space debris collectors navigate danger, corporate politics, and personal ambition in near-future orbit.
Similarities to Sidonia:
Hard sci-fi realism, grounded space hazards, and slow-burn character development.
5. Gargantia on the Verdurous Planet (2013)
- Streaming: Crunchyroll
- Episodes: 13
- MAL Rating: ~7.4
- Studio: Production I.G
- Notable Staff: Gen Urobuchi
Overview:
A genetically engineered soldier is stranded on an unfamiliar planet where war is not the norm.
Similarities to Sidonia:
Culture shock, AI-driven warfare, and questioning the purpose of endless conflict.
6. ID-0 (2017)
- Streaming: Crunchyroll
- Episodes: 12
- MAL Rating: ~6.6
- Studio: Sunrise
- Notable Staff: Gorō Taniguchi
Overview:
Human consciousness is transferred into machines for dangerous space mining operations.
Similarities to Sidonia:
Post-human identity, survival in space, and unconventional power systems.
7. Kuromukuro (2016)
- Streaming: Netflix
- Episodes: 26
- MAL Rating: ~6.9
- Studio: P.A. Works
Overview:
A samurai from the Sengoku era awakens to defend Earth from alien invaders using ancient technology.
Similarities to Sidonia:
Alien warfare, evolving tech, and outsider protagonists adapting to modern threats.
8. Blame! (2017 – Film)
- Streaming: Netflix
- Episodes: Feature film
- MAL Rating: ~6.9
- Studio: Polygon Pictures
- Awards: Annecy Official Selection
Overview:
A lone traveler searches for humanity in an endlessly expanding megastructure.
Similarities to Sidonia:
Same creator, minimalist dialogue, existential dread, and Polygon’s signature CG style.
9. Drifting Dragons (2020)
- Streaming: Netflix
- Episodes: 12
- MAL Rating: ~6.8
- Studio: Polygon Pictures
Overview:
Airship crews hunt dragons to survive in a harsh, airborne ecosystem.
Similarities to Sidonia:
Survival-based economy, isolated communities, and humanity versus monstrous forces.
10. Toward the Terra (2007)
- Streaming: Crunchyroll
- Episodes: 24
- MAL Rating: ~7.6
- Studio: Minami Machi Bugyōsho
Overview:
Psychic humans rebel against an oppressive AI-controlled society.
Similarities to Sidonia:
Genetic evolution, persecution, and philosophical sci-fi themes.
11. Gasaraki (1998)
- Streaming: Currently unavailable
- Episodes: 25
- MAL Rating: ~6.6
- Studio: Sunrise
Overview:
Political realism meets biomechanical mecha in a grounded, militaristic narrative.
Similarities to Sidonia:
Minimal exposition, realistic combat, and cold geopolitical storytelling.
12. Flag (2006)
- Streaming: Currently unavailable
- Episodes: 13
- MAL Rating: ~7.0
- Studio: The Answer Studio
Overview:
A war is documented entirely through cameras and surveillance footage.
Similarities to Sidonia:
Detached perspective, realism, and unconventional narrative structure.
13. Majestic Prince (2013)
- Streaming: Crunchyroll
- Episodes: 24
- MAL Rating: ~7.1
- Studio: Doga Kobo × Orange
Overview:
Genetically modified teens pilot advanced mechs to defend Earth.
Similarities to Sidonia:
Underdog pilots, evolving combat systems, and unexpected emotional depth.
14. Kaina of the Great Snow Sea (2023)
- Streaming: Crunchyroll
- Episodes: 11
- MAL Rating: ~6.9
- Studio: Polygon Pictures
- Creator: Tsutomu Nihei
Overview:
Civilizations survive on massive artificial structures in a frozen world.
Similarities to Sidonia:
Same creator, environmental survival themes, and quiet worldbuilding.
15. Argevollen (2014)
- Streaming: HiDive
- Episodes: 24
- MAL Rating: ~6.6
- Studio: Xebec
Overview:
A low-ranking soldier pilots an experimental mecha during a drawn-out war.
Similarities to Sidonia:
Focus on strategy, flawed leadership, and the cost of technological escalation.
## Why These Anime Work for Knights of Sidonia Fans
These series emphasize survival over spectacle, character erosion over power fantasy, and systems that feel hostile rather than empowering. Like Knights of Sidonia, they challenge genre norms, reward patience, and trust viewers to engage with morally complex worlds where survival is never guaranteed.
