The world’s premier mixed martial arts fighting league is holding a big-time event in Japan this September, and the heavyweight headliners for the event came to town to train with some of Japan’s biggest fighters and visit US troops at Camp Zama.

What Is the UFC?

Brainchild of Brazilian Jiu-Jitsu practitioner Rorion Gracie, screenwriter and director John Milius, and fight entrepreneur Art Davie, the UFC launched in 1993 as a tournament to identify the most effective martial art among disciplines such as karate, judo, jiu-jitsu, kickboxing, boxing, wrestling, sumo and sambo. The aim was to find how the various martial arts would stack up against one another in competition.

As the format grew in popularity, more events followed, drawing more and more fighters. Initially, they focused on the discipline they had the most training in, but UFC soon evolved into a mixed martial art tournament, with fighters realizing that they would have to train in a variety of disciplines in order to remain competitive.

Despite its original tagline “there are no rules,” matches are not completely lawless. There are more than thirty acts that are considered illegal, such as head-butting, eye gouging, or biting, which may result in a penalty or even disqualification. A “main event” or championship match lasts up to five rounds, and normal events last three rounds. Each round is five minutes or shorter.

The winner of a match is usually decided by submission, knockout, technical knockout (a referee stoppage, doctor stoppage or corner stoppage), decision, disqualification, forfeit or a no contest. There are eight weight classes in total, starting at Flyweight (125 lbs./56.7 kg.) and going up to Heavyweight (265 lbs./120.2 kg.). Fights are staged in a cage known as “The Octagon.”

Fight Night Japan 2014

Described as the “Battle of the Bulge” by Mark Hunt, the New Zealander’s headline clash with American Roy Nelson is a much-anticipated fight between two of UFC’s most popular heavyweights. Several other Japanese MMA fighters will round out the card, including the UFC debut of female fighter Rin Nakai as she goes toe-to-toe with Miesha Tate. Here’s the fight card as it stands now:

Mark Hunt vs. Roy Nelson

Rin Nakai vs. Miesha Tate

Kyoji Horiguchi vs. Chris Cariaso

Takanori Gomi vs. Myles Jury

Yoshihiro Akiyama vs. Kyle Noke

Norifumi Yamamoto vs. opponent TBA

UFC Fight Night Japan

At the UFC press conference. From left: Takanori Gomi, Hunt, Nelson, Kyoji Horiguchi, Rin Nakai

Mark Hunt

The man known as the “Super Samoan” is set to for his fourteenth bout in Japan, a country he described as being “like a second home.” His love affair with Japan began in 2001 after he won the K-1 Grand Prix Championships at the Tokyo Dome. It was a remarkable victory for a fighter who had only been in the industry for two years.

Prior to that Hunt seemed set for a life of crime: he had been arrested twice, but an altercation outside a nightclub in Auckland helped set him on a very different path. A bouncer witnessed him knocking out a number of people by himself and subsequently invited him to his gym where he trained as a kickboxer.

Hunt quickly earned a reputation as a brave fighter who refused to lie down and surprised many with his early successes in K-1. Following a mid-career lull, when he admitted to losing motivation, the 40-year-old now seems like he is back to his best. Since making his UFC debut in 2010 he has lost just two fights, winning four and drawing one. His next challenge against Roy Nelson, however, could be his most difficult to date.

Roy Nelson

Set to make his debut in Japan, Roy “Big Country” Nelson goes into the fight in good form, having won four of his last six encounters, all of them by knockout. Winner of the tenth season of the Ultimate Fighter series (a reality show that combines an MMA fight tournament with footage of the fighters living and training together—UFC president Dana White hopes to launch a worldwide version of the show within the next year), the Las Vegas–born star is a talented grappler who has a black belt in Jiu-Jitsu, but has also trained in karate and kung-fu.

Known for his bulging gut and his killer mullet hairstyle, Nelson comes across as somewhat of a joke figure, regularly jesting about the cheeseburgers and fries he eats after each bout, but he is a serious and formidable competitor. A quick look at his record of 29 wins and just 9 losses confirms that.

Hitting the Sumo Stable

This is not the first time Nelson has been to Japan: the martial artist has long been a student of the country’s history and culture, so he jumped at the chance to train with some of Japan’s most iconic fighters: its sumo wrestlers. Before the UFC press conference at the Tokyo Hyatt in Shinjuku, Big Country dropped by the Dewanoumi-beya sumo dojo in Ryogoku to practice the fundamentals of this ultimate heavyweight competition. After being outfitted with the traditional sumo mawashi, Nelson got out on the training floor. Standing 6 feet tall and weighing in at about 260 pounds, Nelson is no lightweight. However, sumo is a sport that knows no weight class, and pushing a sumo wrestler around the ring proved to be a real workout. As he said afterwards, “I wish I could train with some of these guys back home! They’re tough to move around, and it’s definitely good practice.”

Nelson picked up quickly on the techniques and the footwork that the sumo use, and while he hadn’t trained in the style before, he could tell that it could pay dividends for an MMA fighter: “A sumo workout would definitely improve your ability as a fighter and your ability to hold a solid base that would keep you from getting taken down.”

Over the weekend, Hunt and Nelson visited US Army Camp Zama in Kanagawa Prefecture to take part in an event welcoming US troops coming back from Afghanistan.

To get your tickets, visit Tokyo Weekender’s Fight Night Japan 2014 tickets portal.