Floyd Mayweather is no stranger to generating headlines. And he created quite a stir on Monday, after announcing his deal to fight Japanese kickboxer Tenshin Nasukawa on Dec. 31 in Saitama, north of Tokyo.

The 41-year-old Mayweather is 50-0 in his boxing career but has never fought professionally under MMA rules. Although he did have a lucrative win over UFC superstar Conor McGregor in August of last year.

After stopping McGregor in ten rounds at the T-Mobile Arena in Las Vegas, he announced his retirement from boxing.

But a few months after his retirement, Mayweather began discussing the idea of jumping over to mixed martial arts and wanted UFC veteran Tyrone Woodley to train him for the contest.

And then a few months later he began to discuss the idea of facing Manny Pacquiao in a rematch, after the two boxers released a video where they were speaking face to face at a recent concert in Tokyo.

Japanese promoter, the RIZIN Fighting Federation, on Monday said rules and the weight class for the bout have not been set.

"We still have some work to do," said Nobuyuki Sakakibara, the RIZIN chairman.

The 20-year-old Nasukawa, speaking at a news conference alongside Mayweather, called it "probably the biggest event of my life so far."

He also vowed to end Mayweather's long string of victories.

"Nobody has defeated my opponent in the past, and I would like to be the man who makes history," Nasukawa said, speaking through an interpreter. "My punch can change history. And I will show that to you. So please stay tuned."

Most of Mayweather's opponents have trouble landing their shots, and Nasukawa believes he can prevail where others have failed.

“I would like to prove with my own fist what others couldn’t do in the past. My opponent looks taller than I thought, I think because of the aura around him, but I think I could hit him,” Nasukawa said.