Peggy was eighteen years old when she became a Gorenger. Her father was a Swiss national, and her mother was Japanese. She was assigned as a chemical analyst to the Hokkaido branch of EAGLE and served as a special weapons engineer specializing in explosives.

Beyond her scientific expertise, Peggy was a master of disguise and highly trained in equestrian arts. Sophisticated and serious, she was a lethal presence on the battlefield, though she remained a fashion icon off-duty, often wearing signature go-go boots and short hot pants.

As Momorenger, she was armed with the Momo Mirror, a jamming device that could confuse her opponents; heart-shaped Momo Cards; and high-impact Earring Bombs, which she hurled with the taunt, "Are You Ready? Here We Go!" She also utilized the Pink Cecily, which could be used to track and spy on opponents.

As the team's engineer, Peggy was instrumental in the creation of the Gorenger Storm and Gorenger Hurricane finishers. Having no vehicle of her own, she rode in the sidecar of the Green Machine and the Green Star.