Shinichi is an office worker in his 40s and has a wife and children, but he was conscious of his mother as the opposite sex.One day, when his family was away, he tried to confide in his mother.Saya refuses once, but after being asked many times, the two of them go on a trip without telling their families.Today's only promise... To help her son, I tell myself so, but my body asks for a man.The intention of only one time drowns in pleasure and crosses over and over again...