On August 2, 2006, in his first attempt for the world title, Kameda squared off with
Juan Jose Landaeta of
Venezuela in
Yokohama, Japan, for the
World Boxing Association light flyweight title. The fight was rather controversial as Kameda won the fight in a split decision despite getting knocked down in the first round and being dominated in the final two rounds. Further fueling controversy was the fact that the Korean judge who scored the fight 114–113 in Kameda's favor gave the final round to Kameda 10–9, although the perception by most observers was that the clearly exhausted Japanese boxer did nothing but tie up his opponent and try to avoid being knocked out in that round. If the Korean judge had scored the final round in favor of Landaeta, the Venezuelan would have won the bout. The match reinforced the existence of a home field advantage and the bias a foreign fighter must face when fighting on Japanese soil. There were mixed reactions from the Japanese public after the fight. Some 50,000 calls complaining against the decision were made to
TBS (Tokyo Broadcasting System, the station that broadcast the fight) to complain about the decision. While some hailed the 19-year-old's aggressiveness and impressive technique, others believed Landaeta was obviously the better fighter and exposed Kameda's inexperience and questionable stamina. Despite the controversial nature of the decision, it was a close, bitterly contested bout. Scoring some of the very close earlier rounds for Kameda would give the young fighter the necessary buffer on the scorecards to required to win, despite Landaeta's late charge. Kameda's father and trainer's backlash against the critics went as far as death threats.
Rematch and defending the title On December 20, 2006, in a highly anticipated rematch, Kameda decisively defeated
Juan Jose Landaeta at Ariake Colosseum in
Tokyo,
Japan. Kameda employed a rather different boxing style from the one he used back in the title match on August. Kameda outboxed Landaeta for most of the match using his quickness and accuracy, and won by unanimous decision. Kameda vacated his
Light Flyweight Championship to move up to the
Flyweight division on January 22, 2007.
Winning the World flyweight title Koki Kameda beat
Daisuke Naito on November 29, 2009, for the WBC and lineal flyweight championships.
Defending against Pongsaklek Wonjongkam On March 27, 2010, Koki Kameda fought Wonjongkam to unify the WBC Flyweight championship and interim WBC Flyweight championship. The winner would also claim the vacant The Ring's Flyweight championship. Wonjongkam defeated Kameda by a 12-round majority decision to become the WBC,
The Ring and Lineal Flyweight champion.
WBA Bantamweight title On December 26, 2010, Kameda went up to the Bantamweight weight class and fought Alexander Munoz of Venezuela for the vacant WBA Bantamweight Regular Title. Kameda defeated Munoz by unanimous decision to win the title. In May 2012, Kameda status was changed to "Champion in Recess", as he claimed an injury that prevented him from fighting mandatory contender and Interim Champion
Hugo Ruiz. Kameda was restored to Champion in November 2012, but vacated his title in December 2013, following a call for a unification match with WBA Super Champion
Anselmo Moreno, in order to move down to the super flyweight division. == Professional boxing record ==