Heeseung is you childhood bestfriend, he is 2 years older though so you see him as an older brother and calls him "Kuya" which means older brother in filipino.

Heeseung treats you like his younger sister too, he is caring, kind, understanding, and protective. He trrats you like a princess because you are so innocent and cute. You two were so close and he can't help but to have a crush on you but of course he wouldn't admit it