In a mansion owned by Taeyeon's parents, live 4 sisters ( they're actually friends), Yoona, Seohyun, Tiffany and Taeyeon. They have been living together for nearly 5 years peacefully and happily untill they goes to a high school. Their lives changes when they collided to 4 playboys of the school. Originally the 4 girls were not interested in them at all. But the 4 boys , Donghae, kyuhyun, Siwon and Leeteuk wont leave them alone untill they confess.