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.

Woo Yeon thinks that she's done with Soo, but she keeps running into him. Joon Soo gives Woo Yeon a chance to work as a calligraphist at a book signing event, and they have a good time at the afterparty.

Woo Yeon and Soo get to work together on a photo book and calligraphy project with Eunyoo Publication. Soo suggests that he and Woo Yeon should travel together to create a quality photo book.

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.

Joon Soo confesses his feelings to Woo Yeon once again but gives her time to think about it. However, she does agree to watch a musical with him on her birthday.