Upon deciding to return to the ring more than a year into his abruptly announced retirement, Kazuto Ioka only wanted meaningful challenges moving forward. A comeback tour that began with a clear-cut win over Puerto Rico’s McWilliams Arroyo—a 2008 Olympian and two-time title challenger from Puerto Rico—has now transitioned into a history-making junior bantamweight title run.

Six months after becoming Japan’s first-ever male boxer to capture major titles in four weight divisions, the 30-year old impressively retained the belt following a New Year’s Eve win in Tokyo. It came against Puerto Rico’s Jeyvier Cintron (11-1, 5KOS; 1ND), a crafty southpaw and two-time Olympian nearly six years his junior whom the defending titlist defeated via unanimous decision to run his mark to 16-2 in title fights and 7-1 in New Year’s Eve-themed headliners.

“It was a very tough fight with Cintron, who will be a title contender again very soon,” Ioka (25-2, 14KOs) told BoxingScene.com through manager and translator Taku Nagashima, following the first defense of his 115-pound title. “[He is] a tough kid with a lot of heart.

“He could have given up a few times from body shots [absorbed], but remained focused.”

Ioka’s latest win came as part of a year-end tradition dating back to 2011, having fought on New Year’s Eve in eight of the past nine years. His lone loss also marked the lone such occasion taking place outside of Japan, when he dropped a hard-fought 12-round split decision to Philippines’ Donnie Nietes in their vacant junior bantamweight title fight last December in Macao.

The defeat was the lone setback for Ioka—who has previously held titles at strawweight, junior flyweight and flyweight—since returning to the ring in September 2018, with the aforementioned win over Arroyo marking his United States debut. The move brought into the fold veteran promoter Tom Loeffler, who remains involved as Ioka’s stateside representative.

While the bulk of his career has taken place in Japan, bigger game in the division could require him to travel abroad. Fellow divisional titlists Jerwin Ancajas (Philippines) and Juan Francisco Estrada (Mexico—and also the lineal 115-pound champion) primarily fight in the North America market, while England’s Kal Yafai could also fight in the U.S. for the second straight time with his next bout.

Whatever the case, Ioka is in a better place to start 2020 than has been the case for either of the previous two years.

“For now, Kazuto will rest,” notes Nagashima of his client’s immediate plans following Tuesday’s win. “I’ve already started making calls to Tom Loeffler about setting up a big unification bout in the States in 2020.”

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox