Sejun Yoon, who has returned to school, is disappointed that the man he met by chance on the street resembles Seongjae, whom he had a crush on when he was younger. He walks up to the man but realizes it isn't his childhood crush. After that, at a drinking party with their department, Sejun hears that a man who resembles Seongjae is known as the school idol 'Jin Dowon' who has excellent grades, appearance, and personality. That day, Dowon takes Sejun, who is drunk, to his house and they have sex. The next day he makes a suspicious proposal to Sejun, who is surprised. That's right, dating practice... practice! Sejun, who is amazed, thinks DoWon is a madman, and on his way out of the house, steps on an expensive watch that fell on the floor and breaks it...and then...?!