6 Forgotten 90s and 2000s Anime That Took Bigger Risks Than Their Famous Peers

When people revisit anime from the 1990s and 2000s, the same giants usually dominate the conversation. But tucked behind those classics are series that were just as ambitious, sometimes stranger, darker, or more emotionally daring than the titles everybody remembers.

1. Nadia: The Secret of Blue Water

This is the kind of title that feels like it should come up far more often in retro anime conversations. It is a collaboration tied to Hayao Miyazaki and Hideaki Anno, loosely draws from Jules Verne, and still manages to feel like its own distinctive adventure.

At its center is a coming of age story built around Jean, a young inventor, and Nadia, whose pendant attracts dangerous attention. The series gets a lot of mileage from the easy dynamic between Jean, Nadia, and Captain Nemo, and from a world that moves fluidly between aviation, sea travel, and lighter slice of life adventure. It also has a sharper side. As Neo-Atlantis emerges as a threatening force, the story takes on themes of destructive ambition and domination, giving its steampunk charm a much heavier undercurrent.

2. Gunslinger Girl

Plenty of action anime use the girls with guns setup as an excuse for pure spectacle. Gunslinger Girl goes in almost the opposite direction. Rather than glamorizing the premise, it treats it as a way into questions about trauma, guilt, and what repeated violence does to a person.

The Social Welfare Agency takes in orphaned girls, alters them with cybernetic enhancements, and wipes their memories. What follows is not just a stream of missions, but a tense examination of the bonds between the cyborg assassins and their adult handlers. Those relationships are shaped by trust, but also by something much less healthy. The series keeps returning to identity, agency, and manipulation, and its mood is deliberately bleak. That willingness to sit with uncomfortable ideas is exactly what makes it stand out from similar shows.

3. Key the Metal Idol

Few anime from the era sound stranger on paper or more fascinating in execution. This 15 episode OVA combines mecha and cyberpunk ideas with pop idol pageantry, then uses that mix to ask a very old question in a very 1990s way: what does it mean to become real in a world that already feels artificial?

The story follows Tokiko "Key" Mima, a robot who believes that gaining 30,000 friends by becoming a pop idol will let her become human. That premise alone is memorable, but the series pushes further. As Key chases fame, her sense of self begins to splinter, and a corrupt conspiracy puts her life at risk. The result is an unusual collision of identity drama, celebrity culture, and science fiction anxiety that still feels distinct from more famous cyberpunk anime of the period.

4. Fantastic Children

Fantastic Children asks for patience, but it apparently earns it. The 2004 series runs for 26 episodes and builds itself around a mystery that stretches back 500 years, pulling together aliens, reincarnation, and a missing princess into one larger design.

What makes it memorable is not just the number of ideas it juggles, but the confidence with which it brings them together. The story reportedly knows exactly where it is heading, and that sense of control helps the stranger elements connect rather than drift apart. It is the kind of anime that depends on audience trust, then rewards that trust by making its pieces click into place. Along the way, it mixes the grandeur of space with loneliness, fate, and soulmates, giving the whole journey an emotional pull beyond its sci-fi mystery.

5. Master Keaton

Naoki Urasawa is usually linked first to landmark works like Monster, Pluto, and 20th Century Boys, which makes Master Keaton easy to overlook. That is a mistake, because the series sounds like a particularly appealing side of his storytelling instincts: part globe trotting adventure, part mystery procedural, part character study.

The lead, Taichi Hiraga-Keaton, is an archaeologist with an unusually varied background who also investigates suspicious insurance claims. Those cases open onto larger criminal entanglements, but the anime does not hinge on a single long plot. Across 39 episodes, it prefers a case by case structure, letting each installment present a different puzzle. That format highlights Keaton's adaptability and gives the show room to move through a wide range of historical and investigative material. The comparison point is an older, more grounded version of the caper energy people might associate with Lupin the 3rd.

6. xxxHOLIC

If there is a title here that seems tailor made for rediscovery, it is xxxHOLIC. CLAMP has long been associated with bold and unusual work, and this series is described as one of the collective's most thoughtful creations, with an abstract, surreal sensibility that carries over into the anime.

Its storytelling uses a monster of the week framework, but bends that formula into something closer to an anthology about personal weakness and supernatural consequences. Characters arrive carrying burdens and seek out uncanny solutions to fix them. The episodes focus on compulsions such as greed, addiction, and pathological lying, turning each case into more than a simple eerie encounter. That makes xxxHOLIC feel less like a parade of supernatural incidents and more like a series of cautionary tales that push the audience to examine its own choices. For viewers who miss anime willing to be visually strange and morally probing at the same time, this one sounds overdue for a comeback.