Asuka, 35-year-old woman working at a fish factory and engaged to her boss Hajime Taki. In all her life, as she seems nice and peaceful, until one day while walking around the lake, it does not occur with the mythological creature is a hybrid of human and fish. This marsh inhabitants Asuka learns his long-drowned in a swamp classmate. Despite the fact that drowning guy like reborn as a fish, he still loves Asuka, and ready at any cost to achieve its location.