Marshmallow★Imouto★Succubus★

Sweet, innocent, and completely normal — that's how Saki appears, until their father drops some unexpected news: there's a succubus living inside her. That's the setup for Marshmallow★Imouto★Succubus★, a two-episode OVA from T-Rex based on the visual novel by Dwarfsoft. The premise kicks off when Keisuke has a vivid, unsettling dream about Saki acting very out of character, and just when he's relieved it was only a dream, reality complicates things fast. Now he's stuck trying to figure out how to protect his sister's normal life while the supernatural side of her keeps pushing back against that. The show leans into the tension between Keisuke's protective instincts and the situation he can't fully control, set against the mundane backdrop of home and school life. That contrast between ordinary daily settings and the succubus element gives it a slightly offbeat supernatural flavor compared to similar titles. The multiple narrative outcomes pulled from the source material also mean the story doesn't just go one direction, which keeps things from feeling too predictable. If you've watched Imouto Paradise! or Oni Chichi and want something that adds a light supernatural angle to the usual setup, this scratches that itch. It's a short watch at two episodes, so the pacing moves quickly without much buildup. Japanese voice acting does solid work making the characters feel distinct. Niche, specific, and exactly what it says on the label.