順天堂大学
Watanabe was born in Miyagi Prefecture on April 18, 1973. After graduating from Juntendo University, he joined Japan Football League club Brummell Sendai (later "Vegalta Sendai") based in his local in 1996. Although he could not play at all in the match until 1997, he played many matches as center back and left side back from 1998. The club was also promoted to J2 League from 1999. However he left the club end of 1999 season.