Twenty-eight-year-old Kazuto Ioka, who won world titles in three separate weight classes, announced Sunday that he will hang up his gloves and retire from the ring.
"I'm satisfied with myself because I could win in three classes, which is also the reason why I started boxing," Ioka told a press conference.
In a message to his fans, he said, "I think I'm here now because of your support, and I want to express my greatest appreciation."
In 2012, in the third defense of his WBC minimumweight crown, Ioka won the WBA minimumweight title from champion Akira Yaegashi, becoming the first Japanese to unify a title sanctioned by those two bodies.
In 2014, he failed to win the IBF flyweight crown in the only loss of his career, but took the WBA flyweight belt the following year and defended it four times.
Ioka was scheduled to defend that title for a sixth time on Sunday, but relinquished his belt in November, after his father announced he wasn't ready to fight due to insufficient training following his marriage to singer Nana Tanimura.
When asked if his marriage had affected his decision to retire, Ioka said, "I haven't felt any influence fighting since we've been together. My wife's presence itself was my support."
The younger Ioka won 13 title match victories in his career, going 22-1 with 13 KOs.