On her first day at her new school Na-Mi is bullied by others. Coming to her help is a group of girls. Na-Mi quickly becomes part of their group. Twenty five years later, Na-Mi is married to a successful businessman and has a beautiful daughter. Her life seems perfect from afar, but there's something lacking in her life. One day, Na-Mi bumps into high school friend Choon-Hwa in the hospital. They are ecstatic to see each other, but Na-Mi receives a phone call and has to leave. On her way out she ask Choon-Hwa if there is anything she can do for her. Choon-Hwa at first says no, but after a moment of reflection she makes a simple request to Na-Mi. Choon-Hwa asks Na-Mi to find the other members of "Sunny," so she can see them one more time ...