Born in Matsudo, Chiba Prefecture in 1979.
Majored in theater and film arts at Waseda University’s No. 1 School of Humanities and Social Sciences.
While enrolled there, Watanabe made his scriptwriting debut when he was selected to write for “Cherry,” a late-night “Sin-D” drama aired by Nippon Television.
Engaged in various works since graduating from Waseda University in 2002.