Mother, Kayo, has been worried about her son Masaki's strange behavior since he went on a school trip for his club activity. Upon hearing from her husband, it seems that during the trip, Masaki had a wet dream and was ridiculed by his teammates... As her son reached puberty but lacked sexual knowledge, Kayo decided to teach him 'at least how to ejaculate' without telling her husband, performing fellatio on Masaki. However, this half-hearted help backfired, leading Masaki to beg for further sex education. Eventually, they ended up practicing 'sex' together...
