Floyd Mayweather will indeed return to the ring on New Year's Eve in Japan, but it will be only an exhibition.

Mayweather and Japanese kickboxing star Tenshin Nasukawa will meet in a three-round match under straight boxing rules at the 37,000-seat Saitama Prefecture Super Arena in Saitama, Japan -- about a half-hour drive from Tokyo -- the fighters announced during a media availability Thursday at the Mayweather Boxing Club in Las Vegas.

The fight will take place at a contract weight of 147 pounds, the welterweight division limit, with boxing-standard three-minute rounds. The fighters will wear 8-ounce Rizin-brand boxing gloves.

Because the fight is an exhibition, whatever happens will not count on either fighter's official record. No judges will be employed, so if it goes the distance no scores will be rendered.

The announcement was an about-face from just a few weeks ago.

In early November, the Rizin Fighting Federation, a Japanese promotional company founded in 2015 that puts on MMA and kickboxing events, announced the fight at an elaborate news conference in Tokyo, with both fighters in attendance.

Rizin officials and the fighters were light on details of the fight, however, and two days later, after Mayweather returned to the United States, he wrote on social media that he had never agreed to the bout -- even though he participated in the news conference and spoke about the event at length.

But Rizin officials were confident they could keep the fight together, and Thursday they made it official and provided the specifics, though how much money Mayweather will earn was not disclosed. The officials also did not announce an American broadcaster.

"This is a great way for me to go out there and give people some entertainment," Mayweather said. "It's an exhibition match, but it's giving me a chance to do something different. I love competing against fighters from all walks of life like in my amateur days. It's all about entertainment. Nine minutes of entertainment. It's going to be amazing.

"I'm in the entertainment business. That's what I go out there to do. I love to do this. I'm working out to put on a show for three rounds. I'm going to go out there, have fun and do what I do. I'm enjoying life, and I'm going to enjoy this experience."

Mayweather (50-0, 27 KOs), 41, of Las Vegas, came out of a two-year retirement in August 2017 and knocked out UFC superstar Conor McGregor in the 10th round of a massively hyped boxing match in what became the second-highest grossing event in combat-sports history, behind only Mayweather's 2015 victory over Manny Pacquiao.

In September, Mayweather said he planned to come out of retirement again and announced he would face Pacquiao in a rematch in December. Although Mayweather still has said he plans to fight Pacquiao again, it wouldn't happen until at least the summer, with Pacquiao scheduled to defend his secondary welterweight belt against Adrien Broner on Jan. 19 in Las Vegas.

In the meantime, Mayweather will stay somewhat active with the unusual fight against the 20-year-old Nasukawa, who is 27-0 with 21 knockouts in kickboxing and 4-0 with two knockouts in MMA fighting mainly as a featherweight and junior featherweight. He will move up in weight to fight Mayweather, a five-division world champion who spent years dominating the welterweight division.

Nasukawa, who was visiting Las Vegas for the first time for Thursday's media gathering, said he was excited for the fight even if he can't use his powerful kicks.

"The fight is very close and I'm training hard every day to face Mayweather and leave a mark," he said through an interpreter. "This is a great opportunity and we're happy to take it. I'm going to put everything out there and show my strengths. I think that I'm the faster fighter. I'm going to use my weapons against him. There's never been a Japanese fighter to face Floyd Mayweather in the ring. As an athlete, this is something that's a great honor and a challenging task. I'd like to make a big impression.

"I want to get the whole fight community, the whole country of Japan and the entire world involved in this fight. I'm going to go in there believing in myself and ready to prove myself."

Exhibition or not, the fight will be Mayweather's first outside of Las Vegas since he knocked out Sharmba Mitchell in the sixth round in November 2005 at the Rose Garden in Portland, Oregon.