Incumbent Tadatoshi Akiba and his four challengers filed their candidacies Sunday for the Hiroshima mayoral election Feb. 2, election officials said.
The challengers are Shin Ota, 56, a former Hiroshima deputy mayor; Takeshi Koba, 66, a former manager of the Hiroshima Carp pro baseball team; Kazue Funada, 52, a nonprofit organization activist; and Hisashi Nagira, 53, a businessman.
All five are running as independents.
Ota is backed by two of the three ruling parties -- the Liberal Democratic Party and New Komeito. Akiba, a former Diet member of the Social Democratic Party, is supported by the SDP and the Japanese Communist Party.
Koba, who has gained no backing from any political party, is seeking support from among voters with no party affiliation.
With no major issues on the table, the election is widely viewed as a match among Akiba, Ota and Koba.