Three nights before enlisting, Seung-wook decides to leave his mark since he can't avoid the military so he flirts with everyone. However, his school senior So-yoon nor his blind date Il-hong will fall for him. The night before he leaves for the army, Seung-wook decides he's going to see some action with the two girls. The project of 'leaving a mark' starts now.

During the late period of the Joseon, Jae-won, Man-ki, Deok-ho and foolish Chil-deuk are the only ones at the village school. The school is going through a rough patch so the school teacher visits his girlfriend the gisaeng and suggests to his students that they bring in female students. So-hyang and the other girls brighten up the mood of the school and more male students sign up. Yeon-hwa is jealous of Jae-won and So-hyang who fell in love with each other at first sight. She confesses her love to him but he doesn't give her any attention so she tells him So-hyang's secret. On the other hand, the teacher's wife is surprised to see a man wearing a mask peeking at her body but is surprised to the see the size of the hole in the pumpkin he dropped. Not happy with her husband's night skills, she calls in the male students one by one to find out but the pumpkin belongs to no one... To whom does the hole belong to?

Seong-jin, the so-called expert of theory, who learned about women through text only, feels the thrilling excitement whenever he sees his academic advisor professor, Mi-ae. However, Mi-ae keeps ignoring his courtship, telling him to come back after growing up. He felt stuck and helpless and ends up revealing his distress to Yeon-hwa, a novelist who has recently moved to his next door. To his surprise, she says she will teach him about women and begins tutoring him with the real life lessons from kissing to sex.