Erotic Encounter of the Alien Kind

When an alien named Halley literally crashes into ordinary high school girl Inori Amano and, while patching her up, accidentally upgrades her — smarter, more athletic, better-looking, and several cup sizes larger than she started. Halley decides to stick around and monitor her for research purposes, which sounds harmless enough until Inori's feelings for her classmate Sugiuchi come into the picture, and things get complicated fast. The sci-fi framing is a genuinely fun wrapping for a hentai OVA — it gives the story a reason to exist beyond just getting to the explicit content, which is more than a lot of entries in the genre bother with. Halley's presence as this awkward alien observer adds a weird, almost comedic layer to the whole setup. It's a single episode, so there's no commitment involved. If you've watched something like Resort Boin or Kanojo x Kanojo x Kanojo and appreciated when hentai OVAs put at least a little effort into premise and character, this scratches a similar itch. It won't blow your mind narratively, but the alien-intervention angle makes it feel distinct from the usual setup. For what it is — a short, complete story with a sci-fi hook and solid character design — it does exactly what it sets out to do without overstaying its welcome.