New Year's Eve is fast approaching, and with it comes the wacky, wild showdown between top boxer Floyd "Money" Mayweather and kickboxing prodigy Tenshin Nasukawa. While the pairing is a tasty one at face value, fans haven't had much opportunity to get excited over it simply because so few people know what is actually happening.

The announcement of the fight was met with surprise, the aftermath was fraught with controversy, and the weeks since haven't really helped to clear anything up. Details on things like the rules and format of the fight have slowly trickled in, and even now, there are plenty of question marks surrounding Mayweather vs. Nasukawa, as well as the Rizin 14 card it will take place on.

With that in mind, Bleacher Report is here to compile all the key details surrounding the December 31 fights in Tokyo. 

What rules will these two be competing under? When will the fight take place? Is it worth paying for?

Where and How to Watch Mayweather vs. Nasukawa, Rizin 14

Rizin 14 will take place on New Year's Eve, December 31, at the legendary Saitama Super Arena just outside of Tokyo, Japan. The event will begin at 3 p.m. local time, which means it will kick off late at night on December 30 for those watching in North America (1 a.m. ET on Dec. 31; 10 p.m. PT on Dec. 30). 

Rizin Fighting Federation promotes bouts in a number of different combat sports including MMA, kickboxing and shootboxing. Though the Floyd Mayweather vs. Tenshin Nasukawa main event will be a boxing match, the vast majority of contests set to take place in Tokyo will be MMA bouts.

The full card currently stands as follows:

• Tenshin Nasukawa vs. Floyd Mayweather Jr.*
• Kyoji Horiguchi vs. Darrion Caldwell
• Kanna Asakura vs. Ayaka Hamasaki
• Rena Kubota vs. Samantha Jean-Francois
• Yusuke Yachi vs. Johnny Case
• Ulka Sasaki vs. Manel Kape
• Yuki Motoya vs. Justin Scoggins
• Nobumitsu Osawa vs. Tofik Musaev
• Jiri Prochazka vs. Brandon Halsey
• Justyna Haba vs. Shinju Nozawa Auclair
• Damien Brown vs. Daron Cruickshank
• Mika Nagano vs. Miyuu Yamamoto
• Gabi Garcia vs. Barbara Nepomuceno
• Kazuyuki Miyata vs. Erson Yamamoto

Additionally, before Rizin 14 begins, another separate seven-fight card, Rizin: Heisei's Last Yarennoka, will take place:

• Tatsuya Kawajiri vs. Satoru Kitaoka
• Kai Asakura vs. Jae Hoon Moon
• Kana Watanabe vs. Shizuka Sugiyama
• Yuta Uchida vs. Takuma Konishi**
• Nanaka Kawamura vs. Ai Shimizu
• Mikuru Asakura vs. Takeshi Inoue
• Taiju Shiratori vs. Yoshiya Uzatsuyo**

As of this writing, it is unknown where the Rizin 14 event will air outside of Japan and what sort of price tag it may carry. It is also unknown whether the Heisei's Last Yarennoka card will be included, sold separately or not made available at all. This piece will be updated once details are confirmed.

*- Three-round boxing exhibition
**- Kickboxing match

The Tale of the Tape

Tenshin Nasukawa

Age: 20
Height: 5'5"
Weight: 125.6 pounds
Stance: Southpaw
Boxing Record: 0-0 (27-0 in Kickboxing)
Rounds Fought: 0
Trainer: Hiroyuki Nasukawa

Floyd Mayweather

Age: 41
Height: 5'8"
Weight: 147 pounds
Stance: Orthodox
Record: 50-0 (27 KO)
Rounds Fought: 397
Trainer: Floyd Mayweather Sr.

The Rules

Mayweather vs. Nasukawa will be a three-round exhibition match under standard boxing rules. Though Nasukawa is an accomplished kickboxer, he will be unable to use those skills and will largely be forced to play directly into Mayweather's skills.

The Records

Because this contest is an exhibition, it will not be recorded on either fighter's professional record. This means both will have their undefeated records stay intact...at least on paper.

The Stakes

Mayweather has essentially nothing on the line here. Short of being knocked out cold in embarrassing fashion, his reputation will be untarnished regardless of how this bout goes.

Nasukawa, however, has a huge opportunity. Though this is an exhibition boxing match, the 20-year-old could get some real global shine with a strong performance. It's tough to imagine him doing so, however, given how he'll be competing against the greatest boxer in decades.

Who Is Tenshin Nasukawa?

The turn of the millennium was a special time for combat sports in Japan. K-1 and Pride FC were the biggest promotions in the world, packing arenas to the brim and luring tens of millions to their televisions.

It was a stretch unlike anything seen before, and a young Tenshin Nasukawa grew up in the thick of it. 

Six years old and taking karate classes alongside his parents and siblings, a young Nasukawa watched the giants of that era step into the ring and put fans firmly on the edge of their seats. Just like that, Nasukawa's fun family activity became something much more, and it wasn't long after he was headlining shows in those same stadiums.

By age 13, Nasukawa was competing as an amateur kickboxer. By 16, he won his first championship. 

He found his way to an international stage with Rizin FF in 2016 and established himself as the organization's top star by delivering a steady stream of dazzling knockouts. In September, he cemented himself as the top star in all of Japan by besting Rizin's top mixed martial artist, Kyoji Horiguchi, in the main event of Rizin 13.

With little room left to grow in his home country, he now has his eyes set on the rest of the world, and there's no better way for him to take over than taking out Floyd Mayweather.

Floyd Mayweather vs. Tenshin Nasukawa Timeline

January 30, 2018: Mayweather Begins Teasing (Yet Another) Return

Floyd Mayweather came out of retirement to face Conor McGregor in the ring in 2017. He then claimed he was hanging the gloves back up shortly thereafter. That didn't last long, though. On January 30, Mayweather posted the first of a series of teases that he would be transitioning to MMA. That move never came about, but it did show that Mayweather was far from finished in the ring.

September 15, 2018: Mayweather Meets with Manny Pacquiao at Tokyo Music Festival

Mayweather has gone to and from Japan a few times in 2018, with the first on-the-record visit occurring in September. At a music festival in Tokyo, he met with Manny Pacquiao and stated his intent to return to the ring for a rematch with the Filipino pugilist in December. 

September 19, 2018: ESPN Reports Mayweather's Plans to Fight in Japan

How Mayweather and Rizin came together remains something of a mystery, but rumbles of the union first came shortly after the music festival when Mayweather talked to TMZ. He detailed plans to take something of a tuneup fight ahead of the Pacquiao rematch, and he specifically discussed the possibility of facing a kickboxer or mixed martial artist. 

How deep into talks was he with Rizin at that point? What brought them together? And does he still plan to face Pacquiao? All these things remain mysteries at this time.

November 5, 2018 (Tokyo): Rizin FF Announces Mayweather vs. Nasukawa

After a stretch of silence from the Money Team, Rizin FF made the shocking announcement on November 5 that Mayweather would face Tenshin Nasukawa at Rizin 14 on New Year's Eve. It was a surreal sight on every level as the top boxer and kickboxing prodigy sat alongside MMA promoter Nobuyuki Sakakibara and pro wrestling legend Nobuhiko Takada. 

November 7, 2018: Mayweather States Fight is Canceled

Less than two days after the fight announcement was made, Mayweather took to social media to declare that, no, he had not agreed to fight Nasukawa. In fact, he had never agreed to fight in Rizin! According to Mayweather, he was mislead into thinking that his discussions with the promotion were about arranging a clandestine exhibition for a group of unknown high-rollers—a claim that, obviously, does not quite pass the sniff test.

It had the feel of a public negotiating power move from Mayweather, who held all the cards and wanted to ensure that the fight would take place under a favorable ruleset for him. It was a wild turn of events, however, and one that still has many fight fans believing the match is off.

November 15, 2018: Mayweather Confirms Fight is Back On!

Those suspicions were all but confirmed a week later. Once again speaking through TMZ, Mayweather revealed the fight was back on and it would be a simple, straightforward boxing match. And not only was it a straightforward boxing match, it was a three-round exhibition match that wouldn't be reflected on his record.

It was a brutal blow for both Rizin and fans, as it killed an intriguing mixed rules contest in favor of what will likely be a low-energy, by-the-numbers performance from Mayweather. Sakakibara confirmed the news in a media scrum days later and could barely hide his disappointment in the turn of events.

What to Expect from Mayweather vs. Nasukawa

It's impossible to guess what might happen in the Floyd Mayweather vs. Tenshin Nasukawa fight...and not in a good way.

As stated, the ruleset is straightforward: a three-round boxing exhibition with no recorded outcome. On its own, that's frustrating, as one of sports' greatest villains leveraged a promotion into offering up one of its young stars for a contest of dubious legitimacy. When one looks at how Mayweather is discussing the bout, however, it becomes even more questionable.

Speaking with TMZ, Mayweather made it clear he had no serious emotional investment in the outcome of the contest. "It's gonna be a little boxing exhibition, no kicking at all. I'm moving around with the guy for nine minutes," he said (h/t MMAMania.com). He continued: "Just because I'm retired from boxing, I still make appearances worldwide and make a ton of money."

Saying that he plans to simply "move around" with Nasukawa raises an eyebrow. So, too, does his labeling this fight as an "appearance." This, alongside Nasukawa expressing frustration over Mayweather, makes it easy to wonder if there might be some shenanigans afoot that could prevent Nasukawa from delivering his best effort.

For his part, Nasukawa seems to be taking this as seriously as he can. He recently spent two weeks training in the United States with Jorge Linares and has plenty of incentive to go all-out. His chances of outboxing a generational talent like Mayweather remain slim, of course, but Nasukawa does have some exceptional skills of his own and could hypothetically catch Mayweather with something.

But will he truly have the opportunity to do so? Or could there be barriers that prevent him from putting in his best effort?

This writer has no clue, and that's worrisome.

Is Rizin 14 Worth Paying For?

Floyd Mayweather vs. Tenshin Nasukawa might not be worth the price of admission for boxing fans, but Rizin 14 as a whole absolutely will be for MMA fans.

New Year's Eve in Tokyo has been the setting for many of MMA's biggest, best fights, and Rizin has done well in carrying on that tradition. While Rizin cards are consistently entertaining, its New Year's Eve specials are a cut above, typically featuring an over-the-top opening ceremony, spectacular entrances for fighters and a grandiosity the UFC doesn't even try to match.

Though this year's installment isn't jam-packed with throwback favorites, it has an excellent balance of signature Japanese MMA absurdity and legitimate, high-level action.

Kyoji Horiguchi vs. Darrion Caldwell is an exceptional cross-promotional championship fight that captures the magic of old-school MMA, and Kanna Asakura vs. Ayaka Hamasaki is a compelling women's MMA bout that stacks up with almost anything that can be found in the West. UFC fans lamenting the death of the men's flyweight division will be able to follow familiar names like Justin Scoggins and Ulka Sasaki. And those looking for a tasteful level of over-the-top action will be well-served by mother-son duo Miyuu and Erson Yamamoto and the women's heavyweight bout between Gabi Garcia and Barbara Nepomuceno.

It's impossible to guess what Mayweather vs. Nasukawa will look like, and there's an off chance that the fight could get scrapped entirely. Still, Rizin is guaranteed fun in a way that few MMA cards are these days. That fact alone is worth the price of admission.