Vastness: Kuukyo no Ikenietachi

Vastness consists of three mini-stories unrelated to each other. The first follows the sexual escapades of a female student who seduces her schoolmates; the second mainly focuses on a treatment of a particular kind received by a man from a female doctor and nurse in a hospital; the third tells the story of a young girl who discovers her sexuality and eventually gets married.

The first story has no gameplay of any kind. The second has a few screens with an adventure-like point-and-click interface. The third is built like a visual novel: at certain points the player is prompted to make a choice that would scarcely affect the main story but add or subtract certain sexual scenes instead.