On Mihama, one of Tokyo's outlying islands, Shinji witnesses the rape of his girlfriend and middle-school classmate, Haruka, then commits an irreversible crime. But the following day, the island is besieged by a tidal wave which wipes out everything. Twenty-five years later, Shinji has a wife and daughter. A childhood friend, Tasuku, presents himself to Shinji and discloses the real truth of his hidden past. Shinji will have to try and protect Haruka again.