Kaoru is among six female survivors stranded on a desert island after a shipwreck, alongside three male survivors. She uncovers the psychological experiments conducted on the island, focusing on personality transplantation.

As violence and psychological manipulation escalate within the group, Kaoru discovers fellow survivor Hiroki harbors multiple personalities. Her investigation into Hiroki's condition reveals a startling replacement: his alter ego has been supplanted by that of Professor Tadokoro, who was presumed dead in the initial laboratory accident.

Kaoru endures the island's brutal experiments alongside the others, pushed to their shared physical and psychological limits.