Incestuous [silence] Incest. My father is next door...

Mio lives with her husband Hiroshi and son Takashi. Hiroshi is a kind man who rarely gets angry, and the three of them have lived happily ever after. However, Hiroshi had become less and less interested in Mio, and that was Mio's only complaint. Unable to suppress her pent-up desires, Mio secretly hides from her husband and has an affair with her son, intending it to be just once. However, that relationship doesn't end once and for all...