Operation 04: Kirei - S1.E4

The episode begins when a young blue-haired woman is shown having sex with a group of weird men, afterwards they throw her into an oubliette where she then emerges as a butterfly. In what seems to be an island paradise, two well-endowed girls called Rui and Kirei are on vacation. As time progresses, they notice that there is something unusual with the natives and the beautiful butterflies that inhabit the island. As they begin to notice these oddities, they begin to have sex with each other and the natives. The episode ends with the girls being gang raped, then thrown down the same oubliette from the beginning of the episode, and emerging as butterflies.