Back in elementary school, Jin Sung-yu left things on a bad note with Ryu Wonha before transferring to a new school. She never really did get over it. Now she's in high school with some key players from her elementary school years: her best friend, Oh Yeonji; the girl she hates, Lee Mi-ae; and her first crush ever, Ryu Wonha. Yup, that Wonha. And it's starting to look like Wonha might not have gotten over what happened between them either.