Keiichi Tsuruoka (鶴岡 啓一, Tsuruoka Keiichi, born May 18, 1940 in Chiba, Chiba) is the former mayor of Chiba, Chiba in Japan, serving from his election in 2001 until his arrest and subsequent retirement in 2009 for corruption-related charges.^[1] He was an independent who had previously served in the Home Affairs Ministry.^[1] He is a graduate of the University of Tokyo.^{[citation needed]}