When it comes to sex, this innocent girl without makeup shakes her huge breasts and transforms into a total slut!!! Sachiko is in love with Suzuki, a fellow part-timer. However, Suzuki finds Sachiko, who looks plain but has a slutty nature, amusing and enjoys playing dirty games with her. He offers Sachiko to a playboy old man living nearby and uses her as a sex toy... Sachiko gradually shows her true slutty side and transforms into a total pervert who demands creampies herself.