Nobuhisa Nakamoto is a Japanese voice actor, actor, host, and designer born on October 10, 1979, in Osaka Prefecture, Japan. He has blood type O and is known to use the stage name The Mash for some of his creative work. Nakamoto initially entered the voice acting industry as part of the first generation of students at the RAMS Professional Education program, making his debut in 2006. After graduating, he officially joined the agency RAMS. His career later took him to WHOOPEE in 2008, and in 2009, he made a significant move to the agency HiBiKi, where he had the distinction of being the first voice actor ever signed to the brand. He remained with HiBiKi until 2013, after which he left to work as a freelance artist.

Nakamoto's career began with his first major role, providing the voice for the titular character Duo in the 2004 anime series Legend of Duo. In this dark fantasy series, Duo is a vampire who reveals a life-giving secret to humanity, only to face punishment from his former best friend, Zieg. Following this debut, he voiced the character Mikki in the 2006 fantasy adventure series Kiba.

He is perhaps best known for his recurring role in the long-running Cardfight!! Vanguard franchise. From 2011 to 2013, Nakamoto voiced the character Doctor Oh (also spelled Dr. O) across multiple installments, including the original Cardfight!! Vanguard series, Cardfight!! Vanguard: Asia Circuit Hen, and Cardfight!! Vanguard: Link Joker Hen. During this time, he also voiced the character Producer O within the same franchise.

Nakamoto also played a lead role in the surreal comedy anime Ishida and Asakura in 2013. He voiced Asakura, one of the two title characters, a high school student with an afro and a slight stutter who is singularly obsessed with becoming a teacher so he can be surrounded by attractive female students. He also played the character Takeshi (also romanized as武) in both seasons of the short-form anime series Weiß Survive (Weiß Survive and Weiß Survive R) in 2009. Other television anime appearances include roles in B-type H-Movie in 2010, where he played several minor characters such as a male student and a graduate student, as well as a researcher in Dragon Crisis! and a male student in Sekirei in 2011.

Throughout his voice acting career, Nakamoto has collaborated with several industry figures on multiple projects. He worked with voice actor Kazuma Horie on both Kiba and Weiß Survive, and with voice actor Atsushi Abe on Cardfight!! Vanguard and B-type H-Movie. He also worked with screenwriter Satoru Nishizono on Cardfight!! Vanguard and B-type H-Movie, and with the prolific screenwriter Toshiki Inoue on both Kiba and Legend of Duo. In addition to his anime work, Nakamoto contributed his voice to several video games, including the role of a warrior, prisoner, and demon in Disgaea 4, the character怪盗5963号 in Tantei Opera Milky Holmes 2, and the historical figure Hua Tuo in the game Raishi.

Nakamoto is recognized as having largely stepped back from an active career as a voice actor. He currently works under the name The Mash for Bushiroad, a prominent Japanese trading card game and media company, where he is involved in the development and design of card games. This shift represents a significant transition from performing in front of the microphone to contributing to the industry behind the scenes.