Shimizu moved up in weight division and won the WBA super flyweight title with a split decision over Hugo Cázares at the Nippon Budokan in Tokyo, on August 31, 2011.
[9] Shimizu who has recovered from injury enough to do his usual training including sparring, and his manager Kaneko held a press conference on 29 November.
The team Shimizu strongly demanded a retraction and complained that the bout between Tepparith and Kameda should be taken place as an intern championship or a title eliminator.
[11][12][13][14] Although Kaneko Boxing Gym were given the almost zero response from the JBC, as the maximum concession, they barely accepted the status quo on condition that the unification match is early implemented.
[15][16] With intense criticism for the WBA and Kameda Promotions, some point out the overall lack of international political power of Japan's boxing gyms.
[17]Shimizu fought against Tepparith Kokietgym in the WBA super flyweight unification bout at the Yokohama Arena on April 4, 2012.