Japan's Koki Kameda poses with his champion belt after defeating compatriot Daisuke Naito during their WBC flyweight boxing title bout in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN SPORT BOXING) 

Japan's Daisuke Naito (L) is punched by compatriot Koki Kameda during their WBC flyweight boxing title bout in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN SPORT BOXING) 

Japan's Koki Kameda (R) is punched by compatriot Daisuke Naito during their WBC flyweight boxing title bout in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN SPORT BOXING) 

Japan's Koki Kameda holds up his champion belt after defeating compatriot Daisuke Naito during their WBC flyweight boxing title bout in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN SPORT BOXING) 

Japan's Daisuke Naito (R) is punched by compatriot Koki Kameda during their WBC flyweight boxing title bout in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN SPORT BOXING) 

Japan's Daisuke Naito (R) is punched by compatriot Koki Kameda during their WBC flyweight boxing title bout in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN SPORT BOXING) 

Japan's Daisuke Naito (L) is punched by compatriot Koki Kameda during their WBC flyweight boxing title bout in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN) 

Japan's Koki Kameda (L) punches compatriot Daisuke Naito during their WBC flyweight boxing title bout in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN SPORT BOXING) 

Japan's Koki Kameda (L) reacts after finishing their WBC flyweight boxing title bout against compatriot Daisuke Naito (R) in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN SPORT BOXING) 

Japan's Daisuke Naito (R) is punched by compatriot Koki Kameda during their WBC flyweight boxing title bout in Saitama, north of Tokyo, November 29, 2009. REUTERS/Toru Hanai (JAPAN SPORT BOXING IMAGES OF THE DAY) 

China's Xiong Zhao Zhong is punched by Japan's Daisuke Naito during their WBC flyweight title bout in Tokyo May 26, 2009. REUTERS/Michael Caronna (JAPAN SPORT BOXING) 

China's Xiong Zhao Zhong (R) is punched by Japan's Daisuke Naito during their WBC flyweight title bout in Tokyo May 26, 2009. REUTERS/Michael Caronna (JAPAN SPORT BOXING) 

China's Xiong Zhao Zhong battles Japan's Daisuke Naito during their WBC flyweight title bout in Tokyo May 26, 2009. REUTERS/Michael Caronna (JAPAN SPORT BOXING) 

Japan's Daisuke Naito (R) battles China's Xiong Zhao Zhong during their WBC flyweight title bout in Tokyo May 26, 2009. REUTERS/Michael Caronna (JAPAN SPORT BOXING) 

Japan's Daisuke Naito (R) battles China's Xiong Zhao Zhong during their WBC flyweight title bout in Tokyo May 26, 2009. REUTERS/Michael Caronna (JAPAN SPORT BOXING) 

Japan's Daisuke Naito (R) is hit by a punch from compatriot Shingo Yamaguchi during their WBC flyweight boxing title bout in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Shingo Yamaguchi is hit by a punch from compatriot Daisuke Naito during their WBC flyweight boxing title bout in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (L) punches compatriot Shingo Yamaguchi during their WBC flyweight boxing title bout in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (R) punches compatriot Shingo Yamaguchi during their WBC flyweight boxing title bout in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (R) punches compatriot Shingo Yamaguchi during their WBC flyweight boxing title bout in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito celebrates during his WBC flyweight boxing title bout against compatriot Shingo Yamaguchi in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (R) celebrates as compatriot Shingo Yamaguchi kneels on the canvas during their WBC flyweight boxing title bout in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (L) punches compatriot Shingo Yamaguchi during their WBC flyweight boxing title bout in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (L) celebrates with his son Ryo after defeating compatriot Shingo Yamaguchi in their WBC flyweight boxing title bout in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (L) punches compatriot Shingo Yamaguchi during their WBC flyweight boxing title bout in Tokyo December 23, 2008. REUTERS/Toru Hanai (JAPAN) 

Daisuke Naito (L) battles with Tomonobu Shimizu during their WBC flyweight boxing title match in Tokyo July 30, 2008. REUTERS/Michael Caronna (JAPAN) 

Daisuke Naito (L) celebrates after knocking down Tomonobu Shimizu during their WBC flyweight boxing title match in Tokyo July 30, 2008. REUTERS/Michael Caronna (JAPAN) 

Tomonobu Shimizu (R) is counted out during his WBC flyweight boxing title match against Daisuke Naito in Tokyo July 30, 2008. REUTERS/Michael Caronna (JAPAN) 

Daisuke Naito (L) punches Tomonobu Shimizu during their WBC flyweight boxing title match in Tokyo July 30, 2008. REUTERS/Michael Caronna (JAPAN) 

Japan's Daisuke Naito is punched by Thailand's Pongsaklek Wonjongkam at their WBC flyweight boxing title bout in Tokyo March 8, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito is punched by Thailand's Pongsaklek Wonjongkam at their WBC flyweight boxing title bout in Tokyo March 8, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (L) and Thailand's Pongsaklek Wonjongkam exchange punches at their WBC flyweight boxing title bout in Tokyo March 8, 2008. REUTERS/Toru Hanai (JAPAN) 

Thailand's Pongsaklek Wonjongkam is punched by Japan's Daisuke Naito at their WBC flyweight boxing title bout in Tokyo March 8, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (bottom) is thrown by Thailand's Pongsaklek Wonjongkam at their WBC flyweight boxing title bout in Tokyo March 8, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito celebrates as he holds up a trophy after defeating Thailand's Pongsaklek Wonjongkam at their WBC flyweight boxing title bout in Tokyo March 8, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (L) and Thailand's Pongsaklek Wonjongkam exchange punches at their WBC flyweight boxing title bout in Tokyo March 8, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (R) punches Thailand's Pongsaklek Wonjongkam at their WBC flyweight boxing title bout in Tokyo March 8, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (R) celebrates after defeating Thailand's Pongsaklek Wonjongkam (L) at their WBC flyweight boxing title bout in Tokyo March 8, 2008. REUTERS/Toru Hanai (JAPAN) 

Japan's Daiki Kameda (C) arrives to the ring as he is flanked by his father and coach Shiro (L) and his brother Koki (R) before the WBC flyweight boxing title bout against compatriot Daisuke Naito in Tokyo October 11, 2007. REUTERS/Yuriko Nakao (JAPAN) 

Japan's Daisuke Naito celebrates as he poses with a trophy after defeating compatriot Daiki Kameda at their WBC flyweight boxing title bout in Tokyo October 11, 2007. REUTERS/Yuriko Nakao (JAPAN) 

Japan's Daiki Kameda (R) receives a warning from a referee during their WBC flyweight boxing title bout against compatriot Daisuke Naito in Tokyo October 11, 2007. REUTERS/Toru Hanai (JAPAN) 

Japan's Daisuke Naito (R) fights against compatriot Daiki Kameda during their WBC flyweight boxing title bout in Tokyo October 11, 2007. REUTERS/Toru Hanai (JAPAN) 

Japan's Daiki Kameda (R) punches compatriot Daisuke Naito during their WBC flyweight title boxing bout in Tokyo October 11, 2007. REUTERS/Yuriko Nakao (JAPAN) 

Japan's Daiki Kameda (L) swings at compatriot Daisuke Naito during their WBC flyweight title boxing bout in Tokyo October 11, 2007. REUTERS/Yuriko Nakao (JAPAN) 

Japan's Daisuke Naito reacts while being tended to in a break between rounds during his WBC flyweight title boxing bout against Daiki Kameda in Tokyo October 11, 2007. REUTERS/Yuriko Nakao (JAPAN) 

Japan's Daisuke Naito celebrates after winning the WBC flyweight title boxing bout against compatriot Daiki Kameda in Tokyo October 11, 2007. REUTERS/Yuriko Nakao (JAPAN) 

Japan's Daisuke Naito (R) swings at compatriot Daiki Kameda during their WBC flyweight title bout in Tokyo October 11, 2007. REUTERS/Yuriko Nakao (JAPAN) 

Japan's Daisuke Naito (L) lands a punch on compatriot Daiki Kameda during their WBC flyweight boxing title bout in Tokyo October 11, 2007. REUTERS/Toru Hanai (JAPAN) 

Japan's Daiki Kameda (rear) punches compatriot Daisuke Naito during their WBC flyweight title boxing bout in Tokyo October 11, 2007. REUTERS/Yuriko Nakao (JAPAN) 

Japan's Daiki Kameda lifts compatriot Daisuke Naito during their WBC flyweight boxing title bout in Tokyo October 11, 2007. REUTERS/Toru Hanai (JAPAN) 

Japan's Daiki Kameda (C) lifts compatriot Daisuke Naito during their WBC flyweight boxing title bout in Tokyo October 11, 2007. REUTERS/Toru Hanai (JAPAN) 

Japan's Daiki Kameda (L) grapples with compatriot Daisuke Naito during their WBC flyweight title bout in Tokyo October 11, 2007. REUTERS/Yuriko Nakao (JAPAN) 

World Boxing Council (WBC) flyweight Japanese challenger Daisuke Naito's (R) hand is raised by a referee after he won the title match with a unanimous decision over Thailand's defending champion Pongsaklek Wonjongkam in Tokyo July 18, 2007. REUTERS/Yuriko Nakao (JAPAN) 

New World Boxing Council (WBC) flyweight champion Daisuke Naito bows to spectators after defeating Pongsaklek Wonjongkam of Thailand at their title bout in Tokyo July 18, 2007. REUTERS/Yuriko Nakao (JAPAN) 

World Boxing Council (WBC) flyweight champion Pongsaklek Wonjongkam of Thailand (R) and Japan's challenger Daisuke Naito exchange punches during their title bout in Tokyo July 18, 2007. Naito beat Pongsaklek to become the new champion. REUTERS/Yuriko Nakao (JAPAN) 

World Boxing Council (WBC) flyweight champion Pongsaklek Wonjongkam of Thailand (L) receives a punch from challenger Daisuke Naito of Japan during their title bout in Tokyo July 18, 2007. Naito beat Pongsaklek to become the new champion. REUTERS/Yuriko Nakao (JAPAN) 

World Boxing Council (WBC) flyweight Pongsaklek Wonjongkam of Thailand (R) raises the hand of Japan's Daisuke Naito, the new champion, at the end their title bout in Tokyo July 18, 2007. REUTERS/Yuriko Nakao (JAPAN) 

World Boxing Council (WBC) flyweight champion Pongsaklek Wonjongkam of Thailand celebrates after defeating Japanese challenger Daisuke Naito during their title bout at Korakuen Hall in Tokyo October 10, 2005. Wonjongkam succeeded in defending his title with an unanimous decision after the match ended in the seventh round due to Naito's injury. REUTERS/Yuriko Nakao 

Thailand's champion Pongsaklek Wonjongkam (R) lands a punch in the face of Japanese challenger Daisuke Naito during their World Boxing Council (WBC) flyweight title bout at Korakuen Hall in Tokyo October 10, 2005. Wonjongkam succeeded in defending his title with an unanimous decision after the match ended in the seventh round due to Naito's injury. REUTERS/Yuriko Nakao PP05100128 

World Boxing Council (WBC) flyweight champion Pongsaklek Wonjongkam of Thailand holds up a trophy after defeating Japanese challenger Daisuke Naito during their title bout at Korakuen Hall in Tokyo October 10, 2005. Wonjongkam succeeded in defending his title with an unanimous decision after the match ended in the seventh round due to Naito's injury. REUTERS/Yuriko Nakao