Shiro is a complete mama's boy and even chose a university within commuting distance from home. Furthermore, his sexual interests only arise towards his mother, Rie. Rie, in her prime, secretly wishes to have a sexual relationship with Shiro rather than remain in her sexless marriage. Today, Rie and Shiro are going on a hot spring trip just the two of them. Rie harbors a slight anxiety that she might end up having an affair with Shiro during this trip…
