Masuki Satō, known as MASKING, is a third-year at Shirayuki Private Academy and drummer for RAISE A SUILEN. Inspired by her father, she developed a deep passion for drumming. Her appearance features short dyed-blonde hair with asymmetrical bangs, dark gold eyes, and a signature sukeban-style outfit: high-waisted wide-leg pants, a cropped black top, and a deep red sukajan jacket adorned with white stripes and Hanyo Usagi imagery, completed with black ballet flats. At school, she wears a classic blue sailor uniform with an ankle-length skirt.

Beneath her sharp gaze and rough exterior, Masuki enjoys cute things and bakes cakes. She is straightforward, enthusiastic, and deeply values her RAISE A SUILEN friendships, often engaging in playful banter with bandmate Chiyu. She works part-time at "Ramen Ginga" and frequently discusses cooking. Her drumming is highly skilled yet intensely improvisational, overwhelming bandmates and earning her the "mad dog" nickname—a tendency that once hindered band commitments. At school, she maintains a refined, popular demeanor contrasting her band persona.

Masuki profoundly admires Maya, Pastel*Palettes' drummer, mimicking her speech patterns; Maya reciprocates by calling her "King." Her stage name, MASKING, fuses "Masuki" with this moniker. Her birthday on May 12 coincides with RAISE A SUILEN's debut as THE THIRD at Poppin'Party's 5th Live. She holds a scooter license and enjoys riding but dislikes waking early, often napping anywhere—even floors. Hobbies include reading shounen manga, following the shoujo series "Miracle Drum☆Snappy-chan," and watching anime movies. She eats all foods, favoring ramen and vegetable curry, and stands 170 cm tall.

Previously a support artist, Masuki shares a longstanding professional connection with Rei. In a Tokyo Revengers collaboration, her design adapted Ryuuguji Ken's likeness.