What is the song of Kunzhan Unknown 108?

There is a person in the world who knows some unknown secrets about you. When he makes a mistake, he helps you find the reason. When you secretly love someone, he brings you a message. When you quarrel with your lover, you will run to him crying. You regret that you always think of him when you are in trouble, but you are glad that such a good person has appeared in your life. Maybe you've been together longer than lovers. This man is called a friend.