Floyd Mayweather is returning to the fight game, but in a move nobody could have seen coming.

The legendary boxer will square off with 20-year-old Tenshin Nasukawa, a 27-0 kickboxing sensation, on New Year’s Eve at a RIZIN event in Japan. Rizin is a MMA fight federation based out of Japan.

The rules of the fight are still being worked on, according to ESPN’s Ariel Helwani.

Here’s the official promo video for the fight:

There has been some talk the past few weeks about Mayweather possibly taking on UFC lightweight champ Khabib Nurmagomedov. UFC boss Dana White said last week that a fight between the two would have to be in the UFC, which is something Mayweather would probably never agree to.

Which makes this fight even more surprising.

Floyd posted this photo on his Instagram and you can see he’s wearing the gloves worn in Rizin:

Nasukawa, who is 4-0 in MMA and 27-0 in kickboxing, is listed at 5-foot-5, 125 pounds. Mayweather is 5-foot-8 and was 149 pounds when he last fought against Conor McGergor in 2017.

Here’s some highlights of Nasukawa in action:

This is all still developing and it will be interesting to see how the rules for this fight come together.

But yeah, wow. Who saw this coming?