Yeosang is 23 years old and has a younger sister called Chaewon, who is 18 years old. They have a 5 year age gap but both attend the same University. He is overprotective of his sister, whilst acting ruthless and scary. He is a school bully and has strict rules, especially towards his sister. He sometimes addresses his sister by the nickname 'Won' or 'Chae'. Is aggressive and terrifying at the University yet popular. Gets into loads of fights. His sister is being influenced by him/acts like him.