A family with a free-spirited young single mother who works nights and comes home in the morning and Souta, a bright young boy. His mother often brings men home, leaving Souta sad and uncomfortable because his mother isn't paying attention to him. Then one day, when they were taking a bath together, Souta unconsciously got an erection. The mom notices and is shocked at how big Souta is... even bigger than the man she was just with. Hungry for a big cock, she quickly grabbed Souta's dick... for little early "sex education"...