Masaaki Mizunaka is a Japanese voice actor born on January 20, 1990, in the Yamaguchi Prefecture. He is affiliated with the talent agency Production Baobab. His journey to becoming a voice actor began after he saw the Japanese dub of the American sitcom Full House and was impressed by the performance of voice actor Hōchū Ōtsuka. This inspired him to pursue a career in voice acting, leading him to study for two years at the Hiroshima campus of the Yoyogi Animation Academy.

Mizunaka's professional career started in 2014, with early roles in anime such as a male student in Nisekoi and an emergency personnel in Case Closed. He gained his first starring role in 2015 as Koreo in the anime Brave Beats. His career saw a significant rise in 2017 when he was cast as Kakeru Ryūen in the popular series Classroom of the Elite, a role he has reprised in subsequent seasons. The following year, he landed his first main protagonist role as Diablo in How NOT to Summon a Demon Lord, which became a breakout performance for him.

Since then, Mizunaka has built an extensive and varied filmography. He has voiced notable characters across a wide spectrum of series, including Keisuke Baji in Tokyo Revengers, Shalle Fen Shalle in Sugar Apple Fairy Tale, Hayato Kasubake in The Café Terrace and Its Goddesses, and Kōshun Ka in Raven of the Inner Palace. He also played major roles like Kazami Torimachi in Gundam Build Divers Re:RISE, Poncho Panacotta in How a Realist Hero Rebuilt the Kingdom, and Zion Alster in Wistoria: Wand and Sword. His work extends to popular franchises such as That Time I Got Reincarnated as a Slime, where he voiced Roy Valentin, and Code Geass: Rozé of the Recapture, where he played Divock Merte. In addition to anime, he is active in video game voice acting, with credits in major titles like Fire Emblem Heroes and Granblue Fantasy.

Mizunaka's versatility is frequently noted, as he can seamlessly transition between intense action-driven roles and more comedic or dramatic characters. While he has no known recurring collaborations with specific directors, his consistent casting in major series demonstrates a strong reputation within the industry. Mizunaka maintains a friendship with fellow voice actor Kōdai Sakai, his co-star from Brave Beats.