He is also a successful voiceover artist for TV advertising in Japan. He also provided the Japanese voice of Vamp in the 2008 PlayStation 3 game Metal Gear Solid 4: Guns of the Patriots. Tsukamoto was originally set to play the character in Metal Gear Solid 2: Sons of Liberty (after Hideo Kojima's first choice, Kaneto Shiozawa, died before casting began) but was unavailable due to scheduling conflicts, so Ryōtarō Okiayu was assigned the role instead.