“First love” happens only once and it will always be the “only love”.

Chadjen and Som-O have been friends since their childhood. They go to the same kindergarten, primary, and high schools, but Som-O only realizes that she loves Chadjen when they attend university! Or is he Som-O's true love? But she thinks it can't be because no matter how many years have passed, Chadjen's feelings toward her are still unclear! Will this friendship that blossoms into love turn into true love or one-sided love in the end?