“Sleep with me. Just once is enough. It’ll be something good for you to remember.” One rainy night, Kyousuke Sawaragi picks up Shunya Kasuga, who he once saved along with a stray cat. From that day forward, the three of them start living together. Shunya can’t trust other people, and tries to develop their relationship by sleeping with Sawaragi, but Sawaragi rejects “doing it” without trust or love.Slowly, their relationship begins to change. Then, one day, Shunya disappears!