diomedéa

The movie starts off after the events of Episode 3, when Kisaragi had sunk. The Mikawa Fleet (Furutaka, Aoba, Kako, Kinugasa and Tenryuu) are in the middle of Night Battle. Choukai uses Searchlight and gets medium damage, but they win in the end. A New Fleet Girl gets "dropped", emerging from the sea. It is Kisaragi. Kisaragi is brought back to the temporary base in Solomon Islands, but she is suffering from PTSD and has amnesia, unable to remember anyone from back in the anime, excluding Mutsuki...

Yukami Makoto is a high school boy whose hobby is visiting hot springs. His 100th hot spring visit is at Miyama-kan, an inn run by four poster girls: Tokura, Akino, Tsutsuji and Mitomo. There, Makoto spies Yuri, a goddess of the hot springs, and unexpectedly usurps her powers. Makoto ends up working at the inn.

Izayoi, Asuka, and You have been invited to participate in a Gift-Game at a hot spring village to help the small community there find a new water source. OVA bundled with the eighth volume of the light novel.