Yoon Jeonghan and Xu Minghao are bestfriends since they're 5 years old only, they were very close and they know each other very well. Jeonghan acts like an big brother to him, always take a good care and comforts him when he's down while Minghao does his best to protect him since he's very sensitive and soft hearted.

Minghao and Jeonghan met Jun and Seungcheol who are siblings, and that siblings has a crush on them.