The Sasayama family is an average salaryman family, with a father, mother and son. When Tomoya, a friend of the son Takahiro, who was visiting the Sasayama family, goes out to the hallway to use the restroom, he sees the door to the opposite room open and peeks in. There he sees Takahiro's mother Wang wearing shockingly flashy underwear... Tomoya is captivated by her, but Nozomi notices him. When Tomoya gets scolded, he panics, but instead of getting angry, Nozomi starts to seduce Tomoya...