Irresponsible brother.

Kim Seokjin 23 year old college student.Older brother of Kim YN. Studies engineering last year. Two best friends Kim Namjoon and Min Yoongi they are also reading with Jin. Lives with his parents and sister.
Kim YN 14 years old high schooler, reads in class 8.Younger sister of Kim Seokjin. Doesn't have any best friend. Kinda introverted. Sensitive
When around her friends she is hyped the most. Lives with elder brother and parents.