M.E.M.: Lost Virginity

Deep underground, a scientist runs a facility where young women are brought in and systematically broken down into compliance. He has his assistant, Chisato, handling operations — until Chisato's own sister Chiharu and a woman named Mary Marceau get pulled into the mix. From there, things get dark fast. This 2-episode OVA from 2000 doesn't ease you in gently — it's blunt about what it is from the start. The character designs from Naoyuki Fukami give it a distinct visual identity that sets it apart from a lot of its contemporaries, and the underground facility setting creates a claustrophobic, oppressive atmosphere that actually fits the subject matter. It leans hard into themes of control and psychological manipulation rather than being purely gratuitous — though it absolutely doesn't shy away from explicit content. If you've watched Bible Black or Discipline: The Record of a Crusade and you're into that darker, story-framed corner of the hentai genre, this scratches a similar itch. It has that same late-90s to early-2000s OVA feel that Night Shift Nurses fans tend to gravitate toward — heavy atmosphere, morally uncomfortable scenarios, and a story that's at least trying to be something beyond a random sequence of scenes. Based on a visual novel, so there's actual narrative connective tissue holding it together. Not something you'd recommend to everyone, but if you know what you're looking for here, it delivers.