He debuted as a musician in 1986 as the guitarist for the band Shijin no Chi, later forming the duo Oh!

Watanabe debuted as a member of the band Shijin no Chi, through Epic Records Japan.

[1] After releasing their debut full-length album Milk & Cookies in March 1997, the band disbanded by June.

[1] In 2002, the band's single "Under the Sun" with Bonnie Pink was used as the theme song for the Yōsuke Kubozuka-starring film Laundry.

[4] In 2012, Watanabe worked as the music producer for the NHK drama Hatsukoi,[2] and in 2013 for the anime Nagi-Asu: A Lull in the Sea.