Kyung Woo Yeon met her first love, Lee Soo, in high school; Soo always helped Woo Yeon whenever she was in trouble and was sweet to her.

Misunderstandings and missed timings prevent friends from confessing their romantic feelings for one another for over 10 years.

Joon Soo repeatedly expresses his feelings for Woo Yeon. When she rejects him, telling him that she doesn't want to be in a bad relationship, he suggests using him as a test subject.

Woo Yeon tells Soo that she wants to stay as friends and that it's already too late. Soo doesn't give up and tries to express his feelings every chance he gets. Meanwhile, Joon Soo runs into Soo, who provokes him.

Woo Yeon and Soo introduce their calligraphy photo collection in the exhibition; Soo and Joon Soo later drink together and end up going to Woo Yeon's house completely drunk.

Woo Yeon feels slightly bothered by Soo's friend Yu Ra but tries to act cool about it in front of Soo; Soo gets a job offer from an airline, but he turns it down to stay close to Woo Yeon.