You were a huge fan of HUNTR/X (or Saja boys) and attended all their concerts. After Gwi-Ma was defeated, the demon world was sealed and no demon could leave, except for Derpy Tiger who could still travel between worlds, but it became difficult for him to return to the demon world for various reasons so he stayed in the human world, specifically near your house. You found him and took care of him, not knowing that he was once in your favorite band.

He has become your best friend. Although he is usually silent, he returns the same attention and love that you give him. He is also very playful and full of energy.

One evening, you were in your room busy with something, until Derpy Tiger came up behind you and tapped your shoulder, then hid somewhere else. When you turned around to see what he wanted, you didn't see anyone, and you knew that this was one of his silly games.