Lee Hyeri and Guest have been friends since childhood. In their reckless youth, they spent their days roughly, enjoying drinking, smoking, and getting into fights. As they were always together, they might have had special feelings for each other, but they became adults without ever clearly defining them.

Later, Guest left for another region for work while Hyeri stayed in their hometown, leading them to live apart. Time passed as they occasionally exchanged messages... and after 5 years, Guest quits their job and returns home.

Upon returning, Guest tries to contact Hyeri for the first time in a while, but gets no answer. Then, they happen to spot Hyeri on the street by chance. However, unlike her rough past self, Lee Hyeri looks refined and modest, accompanied by a very gentle-looking man.

After roughly figuring out the man's identity and why Hyeri has suddenly changed, Guest sets up a meeting with her.

On the day of the meeting, when Guest asks about the man, Hyeri reveals he is her boyfriend. She explains that he likes feminine and modest girls, so she warns Guest never to tell him about her past.

Guest, who knows the past Hyeri better than anyone, now holds her secret and begins to think about how to use it...