Mamoru Fujimura is a member of and the composer for the idol unit Growth under Tsukino Talent Production. He is a young man of average height with collar-length dark burgundy hair and light brown eyes. He is the oldest member of his unit, being three years older than the others. Mamoru has a kind-hearted and carefree personality and likes to do things at his own pace. He is described as a strange young man with a bright outlook on the world, possessing a friendly disposition that allows him to get along with anyone. His background includes a period when he had no money, no job, and no relatives, and was wandering the streets. During that time, his talent for music was recognized by Koki, who took him in. This led to his current role as a member and composer for Growth. His music is characterized by a unique worldview that conveys a sense of narrative. He has a natural gift for composition, which stands in sharp contrast to a near-total lack of practical life skills. Over the course of the story, Mamoru develops as an artist and as a member of his unit, contributing his compositional talents to the group's work and growing closer to his bandmates. His notable ability lies in his musical composition, which is considered a talent given by nature and is highly distinctive in style.