Mayu Mayusaka is a junior high school graduate living with her childhood friend, Miko Kurono. She streams content focused on cultivating an online persona centered around beauty, emphasizing cute and aesthetically pleasing subjects. Her streaming activities frequently intersect with Miko's, though their styles diverge as Mayu prioritizes charm and visual appeal while Miko pursues viral popularity. She is part of a trio that includes their rival, Kanna Kagurasaka.

Physically, Mayu possesses long blonde hair extending past her hips and green eyes. Her typical attire consists of dresses, opera gloves, and tights, often accessorized with odango-style buns.

She is present when Miko receives an offer to experience a new virtual reality game, initiating her participation in the subsequent adventures within that game world alongside Miko and Kanna. Her known background is limited to being Miko's childhood friend and roommate; no information exists regarding further character development in later episodes, spin-offs, or other media.