Hyakki

A group of young adults have decided to travel to a mysterious island through a tour line. The island has been deserted of human life and the ruins of a once promising city continue to decay. Each of the group members have a reason to visit the island, including returning to their former homes or embarking on a scavenger hunt. During their visit, strange events start to take place and past memories and sexual emotions began to surface among the group. The tour takes a turn for the worst when several of tourists are found murdered, showing that someone remains on the desolated island.

(Source: Anime News Network)