Kuroshima is a slender beauty with a quiet personality, and a timid female teacher who cannot refuse when asked. Her personality causes her to accept the impure request of a male student and help him ejaculate. The one who witnessed this is the very definition of vulgarity. She is called into the principal's office, threatened with dismissal, and ends up in a relationship, almost a slave contract. At first, Kuroshima is reluctant to do the act, but before she knows it, bodily fluids are flowing from her vagina, and she transforms into a vulgar female. When the principal calls her, she climaxes with a smile and a wet crotch.