UFC star Conor McGregor was not the only one left bemused after Floyd Mayweather’s latest announcement he will return to the ring.It was announced Mayweather is set to meet Japanese kickboxer Tenshin Nasukawa on December 31, in Tokyo, Japan - MMA promotion RIZIN Fight Federation promoting the event.McGregor, who Mayweather beat in August 2017 in a crossover fight that generated an estimated $400 million, took to Instagram to address the shock announcement.In the Instagram post McGregor took aim at Mayweather’s brightly coloured tracksuit, likened him and Nasukawa to Rush Hour Five, while also calling the American’s opponent ‘Jackie Chan’.However, the 20-year-old Nasukawa, who is 27-0 as a kickboxer with 26 knockouts and 4-0 as an MMA fighter, took to Twitter to respond to McGregor, and promised to avenge the Irishman’s loss to Mayweather.“Hello, Mr. McGregor,” Nasukawa wrote.“My Name is Tenshin Nasukawa.“I am not Jackie Chan.“I promise to avenge your loss, so please watch my fight.”

Mystery still surrounds the fight as no confirmation of the ruleset, weight, gloves or rounds have been confirmed - with Mayweather’s stating in the fight announcement press-conference that these details will be announced in due course.

However, Nasukawa seems un-bothered about the terms in which this bout will be competed under, as he claimed his hands have the ability to change history.

“When I was offered this, I accepted right away without any delay whatsoever,” Nasukawa said through a translator at the press-conference.

“I would probably say this is my biggest event in life so far, and I’m very happy this is going to materialise.

“I’m a little surprised myself. Nobody has defeated my opponent in the past, and I’d like to be the man who makes history. My punch can change history. I will show that to you, so please stay tuned.”