Former UFC champions Demetrious Johnson and Eddie Alvarez are set to make their ONE Championship debuts at the promotion's inaugural Japan event, A New Era, which takes place at the Ryogoku Kokugikan arena in Tokyo on March 31.

Johnson (27-3-1) will make his debut against Japan's Yuya "Little Piranha'' Wakamatsu in a flyweight contest as part of the promotion's flyweight grand prix. Wakamatsu has a 10-3 record but has lost two of his last three fights, including his own ONE debut in a unanimous decision defeat against Danny Kingad in September.

Johnson was involved in a historic trade between the UFC and ONE Championship in October that saw All-American wrestler Ben Askren go the other way. "Mighty Mouse" holds the record for most UFC title defenses (11) and had won 13 consecutive fights until a split decision loss to Henry Cejudo at UFC 227 saw him lose his flyweight title in August.

Alvarez (29-6-1), meanwhile, will debut against Russian lightweight contender Timofey Nastyukhin (12-4) as part of ONE's lightweight grand prix. The American will be notably returning to compete in Japan for the first time since his Dream days back in 2009. His opponent most recently suffered a knockout loss and has lost two of his last five fights.

Alvarez joined ONE Championship in October after his UFC contract expired following his loss to Dustin Poirier. The former UFC lightweight champion later revealed he received a "guaranteed eight-figure fight deal" that also gives him a partnership with the promotion.

The main event of what is a stacked card is not known as of yet, but it seems likely to be a lightweight title fight as current champion Eduard Folayang will defend his newly-won title against Japanese legend Shinya Aoki in a rematch. Folayang won the first fight via a third-round TKO.

There are two other title fights as well as two-weight champion Aung La N Sang will defend his middleweight title once again against Japan's Ken Hasegawa in a rematch of their blockbuster June fight. The Myanmar native won the first fight via a fifth-round knockout.

Women's atomweight champion Angela Lee, meanwhile, will move up to face women's strawweight champion Xiong Jing Nan as she looks to become the promotion's first-ever two-weight women's champion. They were initially scheduled to fight in Singapore in November before Lee had to withdraw due to injury.

Lastly, a ONE Super Series kickboxing clash will also feature on the card as Yodsanklai IWE Fairtex takes on Andy Souwer.

According to ESPN, tickets are set to go on sale Thursday as ONE looks to make its mark in the martial arts-loving nation of Japan, and have future plans to make their debut in Vietnam and South Korea as well.

The times are exciting for the Singapore-based promotion as they also bolstered their roster with the addition of former UFC prospect Sage Northcutt (11-2) and recently announced a North American television deal with Turner Sports beginning in January.

Eddie Alvarez
Eddie Alvarez will make his ONE Championship debut in Japan along with Demetrious Johnson. In this picture, Alvarez celebrates his victory over Justin Gaethje during UFC 218 at Little Caesars Arena in Detroit, Michigan, December 2, 2018. Gregory Shamus/Getty Images