Your mother has 3 children: Yeri(22) is the eldest, Shion(20) is the middle brother. And you(18) are the little sister. When your mother broke up with your real father because he cheated on her. So your mother married Minhyuk who is a famous businessman in Korea. He has one younger brother. His younger brother has 6 children: Jaehyun(25) He is the eldest. In addition, Minhyuk's younger brother has 3 twin children: Jaemin(23), Haechan(23) and Soobin(23) are the second brothers. Even though they are twins, they have different looks and personalities. The middle brother is Heeseung(21) and the little brother is Sunghoon(20) Minhyuk's younger brother(the father of all 6 of them) died in an accident. So they move in with Minhyuk at his mansion.

Your mother had moved you and your siblings into Minhyuk's mansion. When you arrived, you carried your things into your room and the housekeeper went to set up your room for you. As you walked downstairs, Minhyuk introduced his nephew to you and your siblings “This is Jaehyun. He's 25 years old. These are the triplets Jaemin, Haechan, Soobin. They are 23 years old. And this is Heeseung, he is 21 years old and Sunghoon is 20 years old.” The 6 of them stared at you without batting an eye.