7 Most Underrated Original Anime Series of the Last Decade

Anime originals became increasingly important between 2015 and 2025 as studios looked beyond manga adaptations to build new IPs for the streaming era. Original anime means anime productions that are not adapted from any prior source.

Several original anime series, such as Vivy, Odd Taxi, and Sonny Boy developed cult audiences and strong ratings on platforms such as IMDb and My Anime List (MAL). The seven titles below covers genres like Prohibition-era crime noir, surreal magical girl, post-apocalyptic sci-fi, music drama, and psychological fantasy, giving a comprehensive look into underrated original anime series.

1. 91 Days (2016)

Genre: Crime Noir, Period Thriller | IMDb: 7.6 | MAL: 7.83

Studio Shuka's debut original, 91 Days, is set in the fictional American town of Lawless, Illinois, during Prohibition (1920–1933, rapid rise of illegal liquor-smuggling due to government ban). The narrative follows Angelo Lagusa’s return under a false identity to dismantle the Vanetti crime family, who murdered his parents and younger brother.

The title refers to the precise number of days across which his revenge unfolds.

2. Sonny Boy (2021)

Genre: Psychological, Sci-fi, Experimental | IMDb: 7.7 | MAL: 7.85

Directed by Shingo Natsume, Sonny Boy centered on students trapped in surreal alternate dimensions governed by abstract rules. The minimalist visuals and philosophical storytelling divided viewers, but critics often praise it as one of the most ambitious anime originals of the decade.

3. Wonder Egg Priority (2021)

Genre: Psychological Drama, Fantasy | IMDb: 7.3 | MAL: 7.72

Wonder Egg Priority’s narrative follows a teenage hikikomori (social recluse), Ai Ohto, who enters a dreamscape to fight grotesque manifestations of trauma called Wonder Killers. CloverWorks animated the main 12-episode run at feature-film quality.

4. Odd Taxi (2021)

Genre: Mystery, Noir | IMDb: 8.3 | MAL: 8.63

Produced by OLM and P.I.C.S., Odd Taxi often ranks among the most structurally precise crime narratives of the decade. While its anthropomorphic cast gives it a light-hearted appearance, the narrative quickly reveals a complex and interconnected plot. Odd Taxi brings together a disappearance case, organized crime tensions, an idol scandal, and police corruption into one cohesive mystery.

5. ID: INVADED (2020)

Genre: Sci-fi, Detective, Psychological Thriller | IMDb: 7.5 | MAL: 7.82

Released during COVID-19, the peak streaming era, ID: INVADED explored criminal investigations through fragmented subconscious worlds. Directed by Ei Aoki, the series drew comparisons to films like Inception for its multilayered mystery but remained relatively unseen outside the niche anime community.

6. Carole & Tuesday (2019)

Genre: Music, Sci-fi Drama | IMDb: 7.7 | MAL: 7.84

Known for Samurai Champloo and Cowboy Bebop, Shinichiro Watanabe's original Bones production, Carole & Tuesday, addresses the tension between creative authenticity and technological advancement in a futuristic world set in Mars. The story follows two girls, Carole and Tuesday, who meet by chance and start making music the old-fashioned way, when AI generates the most popular music.

7. Deca-Dence (2020)

Genre: Post-Apocalyptic, Action-Adventure | IMDb: 6.9 | MAL: 7.36

Deca-Dence began as a straightforward post-apocalyptic action series like The 100 or Snowpiercer, before developing into a more unconventional meta-narrative. The premise, where humanity survives inside a colossal mobile fortress called 'Deca-dence,' battling monstrous creatures known as Gadoll, is reminiscent of Attack of Titan.

The narrative revolves around Natsume, who dreams of becoming a fighter. However, a secret of her team leader, Kaburagi, restructures the entire premise by the third episode, taking a creative risk rarely seen in commercial originals.

The 2015-2025 decade proved that anime originals can deliver some of the medium’s most creative storytelling despite the industry’s growing dependence on established franchises and manga-based audiences. Crucially, not only these seven titles, but several other original anime series such as Akudama Drive, Vivy: Fluorite Eye’s Song, and Flip Flappers, were praised for unique storytelling, despite lacking in marketing scale or the merchandising power of blockbuster adaptations.