2. The film is a humorous story about the middle-aged women in the middle school sisterhood group "Sunny", who used to call themselves the "Seven Princesses", who reunite after 25 years and search for memories of their youth.
3. Transfer student Na-mi (played by Shim Eun-kyung) has just transferred from a small town in Jeolla Province to a new school in Seoul. Being overly nervous causes her to speak in tongues. As she starts her first day at the new school, she is bullied by a group of students and it is a group of girls who help her: Chun Hwa (played by Kang So Ra) who is good at fighting, Rose (played by Kim Min Young) who desperately wants to get her eyelids cut, Jin Hee (played by Park Jin Joo) who is very good at cursing, Kim Yoo (played by Nam Bo Ra) who is a literary girl, Bok Hee (played by Kim Bo Mi) who dreams of one day being a Miss Korea, and Soo Ji who is always very haughty ( Min Hyo-rin). Na Mi quickly becomes part of this team of girls. They change the name of their team to "sunny". They vow to stay together forever, but as they prepare for their school's celebration performance, an incident occurs that causes the girls to go their separate ways.
Twenty-five years later, Na-mi (Yoo Ho-jung) is married to a successful businessman and has a beautiful daughter. Her life seems to be perfect, but she always feels that something is missing.
4. One day, while visiting her mother in the hospital, Nami accidentally meets Chun-hwa (Chen Hee-kyung), and they are ecstatic to see each other. But Nami learns the truth that Chun-hwa is a cancer patient and has only two months left to live. When Na Mi asks Chun Hwa what she can do to help. Chun Hwa makes a request that she wants Nami to find out the other members of "Sunny".