Ioka made his first defense against IBF mini-flyweight champion Kyung-Yun Lee in January, 1988, winning by knockout in the 12th round.
Ioka made his second defense in June, 1988, against Napa Kiatwanchai of Thailand, retaining his title by a 12-round draw.
Ioka moved up to the light flyweight division, and challenged undefeated champion Myung-Woo Yuh, for the WBA light-flyweight title in December, 1991.
In December of that year, Ioka lost a 10-round non-title match to an unranked fighter, and decided to retire from boxing.
Kameda scored a knockdown on the former two division title holder from a left straight and right hook combination, but the referee ruled it as a slip.