5 years later after her father died, Han Kaeun's mother decides to remarry again, which was totally way out of Kaeun's head. She finds out that the man her mother loves is a Chinese kind man, she ends up giving him a chance to love her mother. When Kaeun and her mom moved in to her future stepfather's home, she finds out that she will earn siblings as well. Surprisingly, she meets not one, not two, not three, not four, not five. Scratch that, she gets 12 gorgeous-looking brothers. Even though they were beautiful men, they were strange and inhuman. She enters their life of as a sister of 12 brothers who are actually wolves, and eventually these brothers falls in love with her? All could Kaeun say is, "I'm a sister of 12 gorgeous wolves"