Toshiki Masuda

Toshiki Masuda (増田俊樹), also known as Massuu (まっすー), is a Japanese seiyuu and musical performer from Hiroshima Prefecture, Japan. Born on March 8, 1990, and signed to Toy's Factory, he works across voice acting, character songs, stage performances, and the broader anison and multimedia-idol scene. He is listed at 176 cm tall, weighs 62 kg, has blood type B, and is often associated with his Hiroshima hometown in profile searches. In stage work, Masuda played Yukimura Seiichi until the end of season one in TeniMyu Dream Live 7th as part of Rikkai B. In 2012, he formed the singing unit MaxBoys with fellow seiyuu Yoshimasa Hosoya to support his seiyuu debut, and the unit disbanded a year later. He is also part of Marginal#4 with KENN, Naozumi Takahashi, and Yuuto Suzuki, where he voices Atom Kirihara. More recently, he appeared in the 2026 music reading drama Ashigirl, was interviewed about Yoroi-Shinden Samurai Troopers, and was announced among the cast for the 2027 stop-motion anime Komadori: Mofumofu Parade (こまどり モフモフパレード), keeping him active in anime-related performance projects.