18 Year Old Actress So-jeong's Ultimate Sex: Private secret of Na-yeon and Min-woo, the teacher who teaches herself from old times! As Min-woo's grades go up a lot, Na-yeon invites him to her house for a special class. Usually, she is a calm teacher, but her personality changes whenever she touches her body. Meanwhile, Na-yeon had another student named Jae-hyeon, who knows the relationship between Na-yeon and Min-woo and is jealous, but only enjoys the current situation. A special private tutoring class for two students and a female student, which is secretly conducted, is just beginning.