Mayweather, 41, has signed with Japanese mixed martial arts promotions company RIZIN Fighting Federation and is now set to face 20-year-old Nasukawa.
A world champion at five different weights in boxing, Mayweather has never fought in mixed martial arts and it has yet to be decided what rules and format the fight, which will take place in Saitama, will follow.
"I wanted to do something different. I wanted to display my skills outside the U.S. and be in a special fight," Mayweather said at a press conference in Tokyo on Monday.
"I spoke with my team and with RIZIN and we put it together.
"I have fought in the U.S. for all 50 of my fights... As a professional I haven't had a chance to go outside the U.S. to display my skills and to display my talent for the world."
The bout will take place at the RIZIN 14 event, with Nasukawa having previously competed in the organisation's championships in both MMA and pure kickboxing, winning all four of his contests.