A coming-of-age story and realistic romance about young college “villains” who are still learning about love. Kang Hee Jae desperately wants to appear cool to others, but secretly feels smaller than plankton on the inside. While struggling to forgive his girlfriend Yoo Jin for her “savage” behavior, he winds up gradually transforming into an obsessive monster. Meanwhile, Ban Yoo Jin is a highly intelligent older student at Kang Hee Jae’s college. Because Yoo Jin can never seem to keep a relationship going for longer than 100 days, she starts to worry that she’ll wind up living a lonely life alone. So when younger student Hee Jae boldly shoots his shot, she decides to put him through some intense “training” as they date.