Taimanin Yukikaze

In a near-future Japan overrun by demons, the only people equipped to deal with the threat are the Taimanin — a secretive order of ninja trained specifically to fight supernatural threats. Mizuki Yukikaze is one of them, still in training but already capable, and carrying a personal wound: her mother vanished five years ago without explanation. When a lead surfaces pointing toward Yomihara, a corrupt city operating outside normal law, Yukikaze and her friend Rinko decide to go in themselves rather than wait for answers that might never come. Their target is a place called Under Eden, and getting inside means going undercover in ways neither of them fully anticipated. This 3-episode OVA based on the visual novel wastes no time establishing its tone — dark, tense, and unambiguous about its mature content. The supernatural elements aren't just window dressing either; the demon-world lore gives the whole thing a genuine sense of threat beyond the obvious dangers. If you've seen Taimanin Asagi and want to follow up with more from that universe, this is the natural next step. Fans of Kuroiku: Kedakaki Seijo wa Hakudaku ni Somaru will also recognize the general territory — morally heavy situations wrapped in a fantasy framework. It's not trying to be subtle, and it doesn't need to be. What it does offer is a clear story with actual stakes, characters you care enough about to follow into genuinely uncomfortable places, and a setup that delivers on its premise.