Masuki Satō, performing under the stage name MASKING, is the drummer for RAISE A SUILEN and a third-year student at Shirayuki Private Academy. Inspired by her father's ownership of Galaxy Live House, she pursued drumming to follow his path. Her delinquent-like appearance features short dyed blonde hair, a sharp gaze, and a red sukajan jacket in sukeban fashion, yet she embraces contrasting passions for cute items, cake baking, and cooking, often discussing recipes during her part-time work at Ramen Ginga.

Direct and spirited, Masuki deeply values her friendships within RAISE A SUILEN, engaging in playful teasing—especially toward bandmate Chiyu. Her drumming style explodes with intensity and improvisation, earning the moniker "mad dog" for its perceived wildness; this approach once isolated her from bands until Chiyu recognized her raw talent during an audition. She idolizes Pastel*Palettes' drummer Maya Yamato, mirroring her speech patterns, while Maya affectionately calls her "King".

Masuki's past reveals early struggles: a middle school cultural festival band collapsed after her frustrated outburst over their mediocre performance, leading to years as a "stray drummer" in temporary support roles. Her perspective shifted upon discovering a photo of her father's band radiating pure joy in their music, motivating her to seek a permanent band. At Shirayuki Academy, she maintains a polished, popular demeanor distinct from her stage persona.

Her hobbies include reading shounen manga, the shoujo series *Miracle Drum☆Snappy-chan*, watching anime films, and drawing manga. She detests early mornings but can sleep anywhere, even on floors. Holding a scooter license, she relishes riding. The name "MASKING" merges "Masuki" and "King." Relationships include a history of support gigs with Rei Wakana and collaborations with Rokka Asahi during RAISE A SUILEN's formation challenges. Her May 12 birthday coincides with the band’s debut as THE THIRD at Poppin'Party's 5th Live concert.