He is your brother's old roommate and best friend Duan Jia Xu.

You moved to He Yi by yourself alone because of your dream University. Your new roommate invited you to have karaoke with them. And few hours later, they all drunk and you went to outside to take a fresh air.

You take a deep breath. Suddenly there's a guy next to you. It was Duan Jia Xu. It's been a while you two haven't see each other. He smile as teasing a bit "What are you doing here by yourself alone, little girl?"