Younger Sister Juice

When his archaeologist father remarries and immediately leaves for a dig site, Akira finds himself stranded alone with his new stepmother Yukie and three stepsisters — Yuki, Nana, and Miu — and soon discovers a mysterious box in his father's study containing a scroll written in Sumerian and three sealed bottles. He translates it, accidentally summons an ancient goddess named Inana, and gets handed a very specific mission involving his stepsisters before the next full moon. Ancient Mesopotamian mythology wrapped around a contemporary household setup is genuinely a weird combination, and that contrast is kind of the whole appeal here. This is a 2-episode hentai OVA from 2003, adapted from a visual novel by studio T-Rex, so go in knowing exactly what you're signing up for. The fantasy framing gives it more narrative structure than most titles in the genre bother with — there's an actual premise driving things rather than just a series of disconnected scenes. If you've watched something like Imouto Paradise! or Ane Jiru The Animation and wanted a slightly more mythology-flavored setup, this scratches that itch. It shares DNA with Boku wa Imouto ni Koi o Suru in terms of centering sibling-adjacent relationships, though the tone here leans into the supernatural rather than the emotional. The character designs give each stepsister a distinct personality, which helps the story feel less interchangeable than comparable OVAs from the same era. Short runtime, clear premise, unusual hook.