May 21—For Angelo Leo, the opponent was mandatory (sort of, as explained below).

The fight site was voluntary.

Why, then, is Leo defending his International Boxing Federation featherweight title on Saturday against Tomoki Kameda in the challenger's hometown of Osaka, Japan — on a card promoted by Kameda's family, no less?

The answer, Leo, said, is simple: money talks.

Confidence walks.

So, why not?

Thus, Leo, an Albuquerque native, will make the first defense of his IBF title — won in spectacular fashion last August at Tingley Coliseum with a ninth-round knockout of Mexico's Luis Alberto "Venado" Lopez — in Osaka, a city of some 2.7 million people and the third-largest in Japan.

"Mandatory" being a relative term in the business of boxing, Leo could have taken a different and perhaps less precarious route.

After Leo's upset of Lopez, Top Rank, Inc., the powerful boxing promotional firm that staged the Leo-Lopez card at Tingley, offered to promote Leo-Kameda at the Rio Rancho Events Center in January. But Kameda declined to accept the fight on Leo's home turf.

Top Rank then offered Leo a title defense in Rio Rancho against TR contract fighter Arnold Khegai, with Kameda presumably waiting in the wings. But when Leo received an offer he couldn't refuse from Kameda Promotions, Kameda in May was in and Khegai in January was out.

The math, Leo said, was simple and inescapable. By far, he said — without divulging how many zeroes are involved — Saturday's payday will be the biggest of his career.

"I've got a family and all that to feed," said Leo, who is not married — "not yet," he said — but is the father of 2 1/2-year-old son Aziel. "I've got to look out for what's best for me and my family."

The family includes Leo's father, Miguel, his son's head trainer, and by extension longtime Albuquerque trainer Luis Chavez, a fixture in Leo's corner for the entirety of the fighter's career.

Miguel Leo, Chavez, fitness coach Jonathan Balgame and two sparring partners have made the trip to Osaka, but Leo elected to leave Aziel at home in Las Vegas.

"I thought about (bringing him)," Leo said. "But we decided at the last minute that it would be best for him to stay. Just because it's a different time zone, and we don't want him to get off his routine. I know how he gets when he gets tired."

The seemingly daunting prospect of fighting Kameda in Osaka, Leo said, is less so than it might seem.

For starters, he knows Kameda's style, having sparred with him in the past in Leo's adopted hometown of Las Vegas, Nevada.

Kameda, of course, would have gained some insight into Leo's style at the same time.

"It's a double-edged sword," Leo said, but added, "I thought I got the better of him in the sparring."

Kameda's hometown edge is diluted as well by the bout's championship status.

There might be one Japanese judge, but there won't be three.

"I think they're all from different countries," Leo said. "My team and I looked into that and made sure, you know, that it's on even playing fields."

As for the Osaka crowd, Leo said he's come to realize the Kamedas — Koki (the promoter), Diaki and Tomoki, all former world champions — are not universally popular with the home folks.

"From what I'm hearing, a lot of people don't really like them," Leo said. "I have a lot of Japanese fans that are going for me and want me to win."

For himself, Leo bears no grudges. He and Kameda got along well when they sparred in Las Vegas.

Kameda speaks fluent Spanish, having lived and trained in Mexico in the past. Leo does as well; his father was born in Mexico.

"The encounters I had with him have just been really respectful, everything cordial," he said.

There'll be nothing cordial, of course, in the ring on Saturday. Oddsmakers see Leo (25-1, 12 knockouts) as a solid 4-to-1 favorite, based largely on his shocking, knockout-of-the-year victory over Lopez. Kameda (42-4, 23 KOs), though only two years older at 33, is perhaps seen as slightly past his prime after 46 pro fights during a 16 1/2-year pro career.

As impressive as was his performance against Lopez, Leo said he's a better fighter now than he was then.

"I know I've got more tricks up my sleeve," he said. "I've got, you know, more wrinkles in my game, so I think that'll make the difference in this fight.

"I know I'm in his hometown, but I've come too far in my career to just let it go."

By fight time, Leo will have been in Japan for some 10 days; he celebrated his 31st birthday on May 15. The necessary adjustments — travel fatigue, a 15-hour time difference, food, lodging, culture — have been made.

"You know, I'm pretty comfortable here," he said. "Of course, it's a new culture. It's a new environment for me.

"But I'm adapting well, and I'm taking it all in."

STREAMING: The Leo-Kameda card is scheduled to be streamed on ProBoxTV. If you go to the ProBoxTV app and don't see Leo-Kameda advertised, go to YouTube and do a search for ProBoxTV.

Information on the start time has been spotty. The best guess is that the seven-bout card will began at 1:30 a.m. on Saturday.