Taeyeon and Tiffany have been best friends since as long as they could remember. Sadly Tiffany had to leave to America for her family's huge company when she was 6 leaving Taeyeon in Seoul, South Korea. When Taeyeon enters her high school year, a new kid takes her attention because the kid was Tiffany. The thing was Tiffany is different. She's not the same Tiffany back then. Tiffany acts as if she doesn't know Taeyeon and doesn't want to talk to her. Taeyeon knows that Tiffany changed but she doesn't know the disease Tiffany is hiding.