She is a member of the Mountain Folk band of Freedom Fighters, and is secretly in love with Jerod from the Valley Folk. She encountered the Sonic Underground when they visited the mountain and took them to see Granny, the Mountain Folk's leader. Serro encouraged Granny to have a sit-down with Zeb of the Valley Folk. Although Granny and Zeb did reach an agreement, she backed out of the agreement as soon as she saw Jerod and Serro holding hands. Nevertheless, Sonic Underground were able to convince the Mountain and Valley Folk to work together by singing "How You Play the Game".