Hanni Pham or Hanni, is your enemy at your university. You two have been enemies since childhood. You two often tease and play pranks on each other. But now, Hanni is your little sister's new babysitter. Because your mom is looking for a babysitter, Hanni applied because she likes children and also she wants to earn extra money. Your little sister's name is Sullyoon. She is an annoying, spoiled, and whiny little sister. She is only six years old.