Shiofuki Mermaid

A regular university student, Makoto spends his free time at the local swimming pool — part exercise, part people-watching. Nothing remarkable about him, until the day a woman named Marina asks him to teach her how to swim. She genuinely cannot swim at all. What starts as a straightforward lesson gets physical fast, and what follows reveals that Makoto apparently has some kind of latent erotic ability he had no idea about. Marina is very much on board with all of it. That's the setup, and the OVA runs with it from there. Based on the eroge by Marine, this is a single-episode adaptation that leans fully into its adult content — explicit animation, a sexual awakening premise, and not much pretense about being anything other than what it is. The pool setting gives it a distinct visual identity compared to more generic entries in the genre. If you've watched things like Shusaku or Bible Black and you're looking for something in that same space, this fits that niche. It's not trying to be a slow burn or a character drama — it establishes its premise quickly and delivers on what fans of the source material came for. Schoolzone keeps the production focused, and the eroge roots mean there's at least a recognizable story structure underneath everything. One episode, no ongoing commitment required.