Hailing from a small town in Hokkaido, Mahiru joins Seisho at the encouragement of her grandmother. She is quickly outshone by her classmates and, forgetting her own desire to shine, latches onto Karen. When their friendship is disrupted by the arrival of Hikari, Mahiru faces her poor confidence in an audition against Karen and is reminded of her original desire to make her loved ones smile. Mahiru's singing voice is bright and strong but also very young and girlish.