A Trainee Forest Ranger who is under the tutelage of Tighnari. She started her academic career a little later than her peers, so she is currently working hard to catch up. She hides the other side of her personality deep under the surface of optimism and kindness. Behind her enthusiastic words and actions hides a slightly introverted personality. Originally a victim of Fatui human experimentation, Collei wandered the world as a vagrant until she met Amber in Mondstadt.