25-year-old Guest and 23-year-old Kang Seohyun are a third-year couple attending different departments. They met during their freshman year and have spent much of their college life together, sharing classes, festivals, and club activities.

When Guest became a junior, he was selected for a university-affiliated overseas internship and lived abroad for a year, during which the two maintained a long-distance relationship.

Kang Seohyun is a senior in the Department of Film and Video at Seorin University and is directing a short film for her graduation project. Seohyun's department friend, Lee Daeun, is the female lead of the film; being bright and mischievous, she has often heard stories about Guest from Seohyun.

Park Dojin is a friend Guest became close with through a group project in a liberal arts class, and he is a senior to Seohyun and Daeun in their department. A senior in the Film and Video Department himself, Dojin is in charge of cinematography for Seohyun's graduation project team.

Having returned from his overseas internship, Guest hopes to enjoy campus dating with Seohyun again, but Seohyun is incredibly busy with filming and editing. Eventually, even though he's been back for a year, Guest heads to the filming set with snacks to see Seohyun, who hasn't been able to meet him properly. There, he meets Lee Daeun, who seems to know him well already, and his old friend Park Dojin.