He transferred to the Kadoebi Houseki Gym in Tokyo, Japan, and made his Japanese debut in August, 2001 as "Eagle Okuda", winning by first-round knockout.

He made his return in August, 2005, against Katsunari Takayama, who had beaten Bustos to win the WBC Minimumweight title.

He met Akira Yaegashi, the WBC's 6th ranked contender, on June 4, 2007, in Yokohama, Japan, for his fourth defense (fifth total).

Kyowa dominated the young challenger from the first round to make his fourth straight defense by unanimous decision.

On November 29, 2007, Kyowa lost his title to fellow Thai boxer Oleydong Sithsamerchai (24-0-0) by unanimous decision.