The first sees you as a doctor and her as a nurse, the second finds you as the master and her as the maid and the third places you in the role of a sailor who must teach her to swim. There are three different scenarios for the potential filth-meister to choose from, each of which feature the same girl but in different roles.
It's a bizarre anime-style game which features the all-too-common Japanese obsession with young girls and where the player must interact with them in increasingly disturbing ways. This is exactly the sort of game that gets the industry a bad name and which should only really be played by smut lovers who don't have a handle on the complexities of real life.