The race for Saitama governor began Thursday with five candidates in the running.
The Aug. 25 election was called after the incumbent decided to step down after serving a fourth four-year term.
The race is widely seen as a duel between Motohiro Ono, 55, a former diplomat and parliamentary vice defense minister backed by four opposition parties, and former professional baseball player and sportswriter Kenta Aoshima, 61, who is supported by the ruling coalition of the Liberal Democratic Party and Komeito.