A Young couple find a boad buried under a beach,and are taken to another world where they must face a Deadly cult who want to sacrifice them.

Kobayashi Isamu, a first-year high school student, lives in a family of four with his father, an artist, his mother, an insurance agent, and his sister, an office worker. To make ends meet, he works as a milkman. At school, he is a member of the kendo club and spends his days working out with his seniors. Over time, he has various encounters with a series of girls.