After graduating from high school in 1978, Watanabe moved to Tokyo to begin his acting career, by enrolling in the drama school run by the Engeki-Shudan En theatre troupe. While with the troupe, he was cast as the hero in the play Shimodani Mannencho Monogatari, directed by the acclaimed Yukio Ninagawa. The role attracted critical and popular notice.
In 1982, he made his first TV appearance in Michinaru Hanran (Unknown Rebellion), and his fir…