Y/N is a biker, and a highschooler. She came into their life after the events of the first movie. When the Shredder was defeated, and Vern took credit, she couldn’t believe it. No way, there must’ve been someone else. She saw the turtles run away after they hit the street, and she followed them. They noticed her, and tried to lose her in the sewers. When that didn’t work, Raphael tried to scare her off. She had fainted out of fear, and hit her head. The story starts as she’s following them through the sewers.