Yū Mizushima is a Japanese actor, voice actor, and narrator born Kenji Noda on January 18, 1956, in Tokyo. He is a graduate of Nihon University's College of Art. His career in the entertainment industry began in 1972 when, as a student, he performed the theme song for the tokusatsu series Warrior of Love Rainbowman under the name Kenji Yasunaga. He transitioned to voice acting in the mid-1970s, with one of his earliest roles being in the 1976 anime Laura, the Prairie Girl. In the 1980s, Mizushima became a prominent and popular voice actor, frequently cast as the male lead or heartthrob characters in many anime series, particularly in the magical girl genre produced by Studio Pierrot. As of 2021, he is affiliated with the talent agency 81 Produce.

Mizushima's career is marked by a vast number of voice roles across television animation, original video animations (OVA), and theatrical films. He is known for voicing protagonists in several major series of the 1980s. One of his signature roles from this era is Mars, also known as Takeru Myoujin, in Six God Combination Godmars. He also played Isamu Kurogane, the pilot known as Lance, in the mecha series Beast King GoLion. In the magical girl genre, he was a constant presence, voicing Toshio Otomo in Creamy Mami, the Magic Angel, Riki Muroi in Persia, the Magic Fairy, and Shou Yuuki in Magical Emi, the Magic Star. His other notable roles from this period include Shun Makabe in Tokimeki Tonight and Serge Flora in Hana no Ko Lunlun.

Throughout the 1990s and 2000s, Mizushima continued to work extensively, taking on a wide variety of characters that showcased his range, from comedic roles to villains. His filmography includes Franken-chan in Akazukin Chacha, Ryo Asuka in the Devilman OVAs, Neithardt Müller in Legend of the Galactic Heroes, and Scar's Brother in Fullmetal Alchemist. He also voiced Luigi in the anime special Super Mario no Kōtsū Anzen, Raochu (also known as Laojiu) in Kung Fu Boy Chinmi, and Rand in Shin Megami Tensei Devil Children: Light & Dark. In more recent years, he has taken on roles such as Brokeena in the 2020s adaptation of Dragon Quest: The Adventure of Dai, Napoleon and other characters in One Piece, and the Elder in Kirakira PreCure a la Mode. His filmography also includes the roles specified in the query, such as Nate in LBX Girls, Dai-chan in Katte ni Shirokuma, Tsutomu Sugioka in The Order to Stop Construction (part of the Neo Tokyo anthology film), Kashio Fujita in Gu-Gu Ganmo, Kei Tsukimura in Toki-iro Kaima, Genjin Takahashi in Bug tte Honey, Shukumaru in Fire Tripper, and Will in Chikyū Monogatari Telepath 2500.

Beyond anime, Mizushima has had a significant career in voice-over (fukikae) for live-action foreign films and television series. He is particularly renowned as the official Japanese dubbing voice for Hong Kong martial arts star Sammo Hung, a role he has held for decades across numerous films. He has also dubbed other prominent actors, including Matthew Perry as Chandler Bing in Friends and Michael J. Fox in several films. In the realm of animation dubbing, he is the Japanese voice of Wakko Warner in Animaniacs and Johnny Test in Johnny Test. His work also extends to tokusatsu, where he provided the voice for the character Sorrowful Knight Aigaron in Zyuden Sentai Kyoryuger and Master Elehung Kam Po in Juken Sentai Gekiranger.

In May 2020, Mizushima announced a temporary hiatus from work to undergo surgery for the removal of vocal cord polyps, from which he made a successful recovery. His long-standing and varied contributions to the voice acting industry were recognized in 2020 when he received the Kei Tomiyama Memorial Award at the 14th Seiyu Awards.