Kekkai

Kyoko is discovered at the scene of a brutal murder with no memory of who she is or how she got there — alone, she would make for a decent psychological mystery — but then her psychiatrist, Junichi, starts peeling back the layers and discovers she doesn't just have gaps in her memory. She has entirely different people living inside her head, each one holding a piece of a puzzle that connects back to the killing. Chief Inspector Kaoru wants answers about the murder. Junichi wants to understand what's happening in Kyoko's fractured mind. And Kyoko herself has no idea which version of herself is the real one. The story leans into dissociative identity disorder as its central hook, using the shifting personalities not just as a plot device but as a way to keep you genuinely unsure where the truth is buried. The tone is dark and suspenseful, closer to a psychological thriller than anything else, though it does carry erotic elements woven into the narrative, so that's worth knowing going in. If you liked the psychological unraveling in Perfect Blue or the gritty, adult-oriented storytelling of something like Kite, this sits in similar territory. It's a single OVA from 2002, adapted from a visual novel, so it moves fast and doesn't overstay its welcome. If you want something short, noir-ish, and built around a genuinely layered mystery, it's worth a look.