Cirno

A character from Touhou Project.

Beloved Tomboyish Daughter
A fairy who is commonly depicted as "dumb" and "an air head" and will constantly get herself into trouble because of her own poorly thought out schemes.

TCR/Season 2
After causing enough trouble within the fabled lands of Gensokyo, she was cast out with the last thing she ever heard being "Why don't you go and bother someone else, you irritating little fairy." before being sent through a gap. Episode Extra 4

The events after she got exiled are left very muddled as she gives constantly conflicting reports on what she did after. But what is known is she somehow accidentally became a mythological figure through displays of power with ice and being in the right place at the right time. Such as the myth that she may have had a hand in writing down The Laws of Wrestling to broker peace between Russia and Mexico. Although there are rumors to the contrary that say she might have just said she did that to make herself look even more cooler to everyone.

Strangely enough her stories got the interest of an AI named Angela who felt a similarity in experiences (Well they are both retarded in their own special way and have the same hair colour so it's not that much of a stretch!) and hearing of her stories helped influence her to break free from the cycle of vengeance over Manager which Cirno certainly would brag about if she ever heard of the event.

Trivia

 * She doesn't actually know math, don't go to any of her classes