Satou Masuki is a second-year high school student at Shirayuki Private Academy, an all-girls' Catholic school, which she has attended ever since kindergarten.
She goes by the stage name MASKING (マスキング) and is the drummer for the band RAISE A SUILEN. Her longing to become such a drummer like her father - who is the owner of Galaxy Live House - made her start playing the drums.
Masuki has short blonde hair which barely reaches her shoulders, with asymmetrical fringe, as well as dark gold eyes.
Masuki wears a high-waisted wide leg pants with a cropped black top, over which she wears a deep red sukajan jacket with white stripes and pictures of Hanyo Usagi on the front. She wears black ballet flats without socks. Masuki does not wear any jewelry or accessories. Her style can be described as sukeban.
Despite her sharp gaze and rough, delinquent-like appearance, Masuki likes cute things and is skilled at baking cakes. She is a straightforward but enthusiastic girl with a passionate heart, and values her friendship with the other RAISE A SUILEN members. She loves cooking, as well as talking about it, and even works part-time at a ramen store called "Ramen Ginga".
She is a very skilled drummer, however, when she gets too immersed, she tends to fluster the other band members with her difficult improvisation performances, which made it difficult for her to join a band previously. Because of her violent and impulsive playstyle, she is called a mad dog (狂犬).
Masuki admires Maya a lot and even knew of her before she became Pastel*Palettes' drummer. She even tends to mimic Maya's speaking style when she speaks with her. Likewise, Maya also admires Masuki and calls her "King".
A list of characters Masuki interacts with in the game (during Lives and in the dialogues at the end of every game).
- She and Rei were work colleagues back when they were both working as support artists.
- Adding to this, in an in-game line, Masuki mentions that she and Rei "go way back." This might be a reference to the fact that Natsume used to be play the drums as a support artist for Raychell at one point.
- She has the same height as Kaoru.
- Masuki's birthday, May 12, is the same date when RAISE A SUILEN (at the time, titled THE THIRD) played as the opening act for Poppin'Party's 5th Live, HAPPY PARTY 2018! during BanG Dream! 5th☆LIVE.
- Masuki owns a scooter license.
- She dislikes waking up early.
- Masuki likes reading a shoujo manga series called Miracle Drum☆Snappy-chan (ミラクルドラム☆スナッピーちゃん).
- She also likes watching anime movies.