Joshi daigakusei - Watashi wa shôbu suru (1959)

Pretty young student Junko joins a group of other co-eds on a boating holiday. Between trips they assemble in a cave and play The Cola Game which involves forming a circle and spinning a bottle. Wherever the bottle points decides which couple must make love in front of the rest of the gang, or alternatively the girl must strip. Junko is saved from "a fate worse than cola" by the intervention of Makoto, and the couple decide to live together. Later, while Junko is having an abortion, Makoto goes skiing with another girl, so Junko switches him for hard-working architect Hirakawa. Enraged, Makoto tries to ram their boat with his own, but only succeeds in killing himself on the rocks.