Despite (or because of) its unsettling nature, Imouto Jiru OVA 3 is a cult talking point for two crowds:
It perfectly encapsulates the "magical girlfriend/goddess" trope that dominated late-90s and early-2000s anime, subverting it into an adult comedy context. Imouto Jiru Ova 3
"Imouto Jiru" was adapted into a two-part OVA series, not three parts, which is the first critical detail for any fan looking for a "third OVA". Here is the complete release schedule for the existing OVAs. Despite (or because of) its unsettling nature, Imouto
After being discovered in bed with his stepmother, Yukie, Akira searches his father's study and finds a mysterious box containing an ancient scroll and three bottles. His father had previously taught him the Sumerian language, so he manages to read the scroll aloud. His reading conjures a tiny, naked goddess named Inana, who declares that Akira is now bound to a contract. According to this contract, he must collect the "love juices" (a euphemism for female sexual fluids) of his three stepsisters in the bottles before the next full moon. Failure to do so would result in a "terrible horror" befalling him. After being discovered in bed with his stepmother,
Akira accidentally summons a goddess named Inana. She places him under a contract to collect "love juices" from his three sisters to avoid a terrible fate.
Disclaimer: This paper is a fictional academic exercise analyzing a hypothetical adult animation title. All interpretations are constructed for analytical demonstration.