Kazuto Ioka sees a “challenge to go further” in his clash with Fernando Martinez

Four-division world champion Kazuto Ioka has long courted a unification at junior bantamweight. He thought he’d get it against then Ring champion and WBC titleholder Juan Francisco Estrada late last year only for things to fall apart during negotiations.

However, Ioka, rated at No. 2 by The Ring at junior bantamweight, and his team able to broker a deal with unbeaten IBF titlist Fernando Martinez, and the two will collide at Ryogoku Kokugikan in Tokyo, on Sunday.

“I’m happy to have a unification fight,” Ioka (32-2-1...