Rie Maruyama stands among the sixteen main characters in the CUE! franchise. An 18-year-old aspiring voice actor affiliated with the agency AiRBLUE, she leads its subunit Moon. Her occupational status is that of a freeter, engaging in part-time or irregular work.

Physically, she measures 1.54 meters tall, possesses multicolored hair and eyes, and has blood type A. Her birthday falls on December 18. The kanji in her given name, "利" (ri) meaning "benefit" or "advantage" and "恵" (e) meaning "favor" or "benefit," combine with her surname "丸山" (Maruyama), where "丸" (maru) signifies concepts like "round," "circle," or "complete" and "山" (yama) means "mountain."

Personality-wise, Rie embodies chūnibyō traits, maintaining delusions of grandeur or fantastical beliefs atypical for her age. Her role places her in a position of responsibility, overseeing the Moon subunit within AiRBLUE.