Tokyo - Boxing superstar Floyd Mayweather said on Monday he will come out of retirement to fight a Japanese kickboxer half his age, Tenshin Nasukawa, on New Year's Eve in Saitama.
The 41-year-old unbeaten American, who captured world titles in five different weight divisions and was considered the best pound-for-pound boxer in the sport, out-boxed Irish mixed martial arts fighter Conor McGregor in his last fight in August 2017.
That victory improved his boxing record to a perfect 50-0 but the format or rules for his meeting with the baby-faced Nasukawa were not specified by the Japanese mixed martial arts promoters RIZIN.
Mayweather posted a teaser photo on his Instagram feed at the weekend, showing him wearing kickboxing gloves.
"I want to give the people what they want - blood, sweat and tears," Mayweather told a news conference in Tokyo after reportedly flying into Japan on his private jet.
"I want to continue to build my relationship with Money Team Tokyo," he added, promoting the cross-code bout as an expansion of his businesses into Japan.
"I want to continue coming over here and bringing other fighters so my company can continue to grow and RIZIN can continue to grow.
"We've been making some huge fights happen in the US, but we look forward to taking the Mayweather Promotions banner and the TMT banner worldwide."
Nasukawa, who is described in the press release as "perhaps the best combat sports prospect (Japan) has ever seen", boasts a 27-0 record but has never competed as a professional boxer.
The 20-year-old with a bleached-blond quiff called it an "easy decision" to accept the offer to face Mayweather in Saitama, north of Tokyo.
"Honestly it was surprise offer but I accepted without hesitation," said Nasukawa.
"It's the biggest moment in my life and I want to be the man who changes history. I'll do that with these fists, with one punch - just watch."
Mayweather, who stopped McGregor in the 10th round last year after coming out of retirement for a $275 million pay day, had been flirting with the idea of a rematch with the Irishman or facing fearsome Russian Khabib Nurmagomedov.
"He's young and he's undefeated so it's obvious he's doing something right," Mayweather said of Nasukawa.
"I'm pretty sure he's going to bring a lot of excitement. It's always been a goal of mine to go outside out of the US and display my talent."