Calstone Light O is a character from the multimedia franchise 'Umamusume: Pretty Derby,' which features anthropomorphized racehorses as girls training to become top athletes. Based on the real-life Japanese racehorse of the same name, Calstone Light O is depicted as a spirited and determined Uma Musume who strives to make her mark in the competitive world of racing. In the series, she is known for her perseverance and energetic personality, serving as an inspiring presence for her peers.