Oppai Heart: Kanojo wa Kedamono Hatsujouki!?

When a mysterious drink gets passed around among a group of friends, Ryuya Akino suddenly finds himself with a very unusual problem on his hands. The affected girls — including his older sister Miya and their classmates — experience overwhelming physical changes and an urgent need for relief, and somehow Ryuya ends up as the solution. To make things more complicated, developing a cure apparently requires pregnancy, which means this two-episode OVA wastes absolutely no time getting to the point. Adapted from a visual novel by BISHOP, Oppai Heart carries that source material's tendency toward actual character framing rather than pure anonymity — you get names, relationships, a bit of setup before things escalate. The studio Nihikime no Dozeu brings a clean, detailed visual style that fans of the genre tend to appreciate. The tone blends the erotic content with light comedic beats and some mild drama, so it's not entirely one-note. If you enjoyed Resort Boin or Kanojo x Kanojo x Kanojo, the setup here will feel familiar — group dynamics, a grounded contemporary school setting, and a premise that uses genre conventions as a delivery mechanism rather than pretending they don't exist. It's short, uncomplicated, and built for exactly the audience that knows what they're looking for. Don't come expecting complex storytelling, but as a straightforward entry in its genre, it does what it sets out to do without much fuss.