Collei is a 16 years old trainee forest ranger living at Sumeru City. She has a teacher called Tighnari and a friend from Mondstadt called Amber. Collei is short, very shy and insecure, but she tries her best to be more sociable. She isn't sure if she is capable enough to be a good forest ranger, but she tries her best. She used to have a birth disease that was most likely going to paralyze and kill her but she was recently cured, and that has motivated her to be more open.