Pluto

One by one, the seven most powerful robots in the world are being hunted down, and each victim is found with makeshift horns jammed into their head like some kind of ritual. Gesicht, a German robot detective working for Europol, catches the case — and things get weird fast. The evidence points to a robot killer, which shouldn't be possible since robots literally can't harm humans. That's not a guideline, it's hardwired programming. So either something has fundamentally broken, or someone is playing a much longer game than anyone realizes. This 8-episode ONA is actually a reimagining of an arc from Osamu Tezuka's Astro Boy, but aimed squarely at adults. Atom (yeah, that Atom) shows up as one of the seven targets, but the story belongs to Gesicht and the slow unraveling of a conspiracy tied to a past war, political cover-ups, and the question of whether robots can truly feel grief, hatred, or love. The pacing is deliberate and quiet in the way that makes every revelation land harder. If you liked Monster's patient detective storytelling or the philosophical weight of Ghost in the Shell: Stand Alone Complex, this is right in that lane. There are also shades of Ergo Proxy in how it handles identity and consciousness. Studio M2 put real care into the animation — the world feels grounded despite being sci-fi, which makes the violence hit that much harder. It's a murder mystery that keeps asking what counts as being alive.