Greatest 18 Club Championship

Muhammad Hussain Inoki was a Japanese professional wrestler, martial artist, politician, and promoter of professional wrestling and mixed martial arts. He was best known by the ring name Antonio Inoki , a homage to fellow professional wrestler Antonino Rocca. Inoki was a twelve-time professional wrestling world champion, notably being the first IWGP Heavyweight Champion and the first Asian WWF Heavyweight Champion – a reign not officially recognized by WWE.

Aloysius Martin "Lou" Thesz was an American professional wrestler. He was a three-time NWA World Heavyweight Champion and held the title for a combined total of 10 years, three months and nine days – longer than anyone else in history. Considered to be one of the last true shooters in professional wrestling and described as the "quintessential athlete... a polished warrior who could break a man in two if pushed the wrong way", Thesz is widely regarded as one of the greatest wrestlers of all time and the single greatest wrestling world champion in history, and probably the last globally accepted world champion. In Japan, Thesz was known as the 'God of Wrestling' and was called Tetsujin, which means 'Ironman', in respect for his speed, conditioning and expertise in catch wrestling. Alongside Karl Gotch and Billy Robinson, Thesz later helped train young Japanese wrestlers and mixed martial artists in catch wrestling.

Charles Istaz was a Belgian-born German-American professional wrestler and trainer, best known by his ring name Karl Gotch. In Japan, Gotch was known as the "God of Wrestling" due to his influence in shaping the Japanese professional wrestling style. He has no relation to the earlier wrestler Frank Gotch.

Nicholas Warren Francis "Nick" Bockwinkel was an American professional wrestler. He is best known for his appearances with the American Wrestling Association (AWA) in the 1970s and 1980s.

Johnny Powers was a Canadian professional wrestler. He competed in several North American and International promotions including National Wrestling Alliance (NWA), American Wrestling Association (AWA), Maple Leaf Wrestling, National Wrestling Federation, International Wrestling Association and the World Wide Wrestling Federation feuding with then WWWF World Heavyweight Champion Bruno Sammartino during the early 1960s NWA's Lou Thesz, Gene Kiniski and AWA's Verne Gagne.

John Theodore Wisniski, better known by his ring name Johnny Valentine, was an American professional wrestler with a career spanning almost three decades. He has been inducted into four halls of fame for his achievements in wrestling. Wisniski is the father of professional wrestler Greg "The Hammer" Valentine.

André René Roussimoff, better known by his ring name André the Giant, was a French professional wrestler and actor. Roussimoff was known for his great size, which was a result of gigantism caused by excess growth hormones. It also led to him being called "The Eighth Wonder of the World".

William Alfred Robinson was a British professional and catch wrestler, wrestling instructor and trainer. Robinson was one of the few wrestlers who was successful in several continents, winning titles in promotions nearly everywhere he wrestled. One of the leading practitioners of catch wrestling and a seven-time world champion, Robinson is considered to be one of the greatest professional wrestlers of all time, with legendary champion Lou Thesz once saying he was the greatest ever. Robinson was also well known in Japan where he trained mixed martial artists and professional wrestlers in catch wrestling.

Yasuhiro Kojima was a Japanese professional wrestler and trainer best known by his ring name Hiro Matsuda . He trained many professional wrestlers including Hulk Hogan, The Great Muta, "Mr. Wonderful" Paul Orndorff, Scott Hall, Lex Luger, "Cowboy" Bob Orton, and Ron Simmons.

Robert Louis Backlund is an American retired amateur and professional wrestler. He is best known for his appearances in the World Wide Wrestling Federation/World Wrestling Federation from 1976 to 1984 and in the 1990s, where he held the WWWF Championship/WWF Championship on two occasions. His first reign was the second longest in history as recognised by the WWE. Backlund was inducted into the WWE Hall of Fame in 2013.

Terry Gene Bollea, better known by his ring name Hulk Hogan, is an American retired professional wrestler. He is widely regarded as the most recognized wrestling star worldwide and the most popular wrestler of the 1980s, as well as one of the greatest professional wrestlers of all time.

Muhammad Ali was an American professional boxer and activist. Nicknamed "The Greatest", he is regarded as one of the most significant sports figures of the 20th century and is often cited as the greatest heavyweight boxer of all time. In 1999, he was named Sportsman of the Century by Sports Illustrated and the Sports Personality of the Century by the BBC.

Mitsuo Yoshida , better known by his ring name Riki Choshu , is a South Korean-Japanese retired professional wrestler who is best known for his longtime work in New Japan Pro-Wrestling (NJPW) as both a wrestler and a booker. He is considered one of Japan’s most influential wrestlers for his work in the 1980s and 1990s and is known as the first wrestler to popularize the Sasori-Gatame, better known in English as the Scorpion Deathlock or Sharpshooter. After leaving NJPW in 2002, he formed Fighting World of Japan Pro Wrestling (WJ), but eventually returned to New Japan in October 2005 as a site foreman, booker and part-time wrestler. Choshu once again left NJPW in 2010 and primarily worked in Tatsumi Fujinami’s Dradition, as well as his own self-produced Power Hall events as a freelancer. Choshu was a second generation Zainichi Korean until his naturalization in 2016.

Fukuoka is the sixth-largest city in Japan, the second-largest port city after Yokohama, and the capital city of Fukuoka Prefecture, Japan. The city is built along the shores of Hakata Bay, and has been a center of international commerce since ancient times. The area has long been considered the gateway to the country, as it is the nearest point among Japan's main islands to the Asian mainland. Although humans occupied the area since the Jomon period, some of the earliest settlers of the Yayoi period arrived in the Fukuoka area. The city rose to prominence during the Yamato period. Because of the cross-cultural exposure, and the relatively great distance from the social and political centers of Kyoto, Osaka, and later, Edo (Tokyo), Fukuoka gained a distinctive local culture and dialect that has persisted to the present.

Japan is an island country in East Asia. It is situated in the northwest Pacific Ocean and is bordered on the west by the Sea of Japan, extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans an archipelago of 14,125 islands, with the five main islands being Hokkaido, Honshu, Shikoku, Kyushu, and Okinawa. Tokyo is the nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto.

The IWGP Heavyweight Championship was a professional wrestling world heavyweight championship owned by the New Japan Pro-Wrestling (NJPW) promotion. "IWGP" is the acronym of NJPW's governing body, the International Wrestling Grand Prix . The title was introduced on June 12, 1987, in the final of an IWGP tournament. It was unified with the IWGP Intercontinental Championship on March 4, 2021 to form the new IWGP World Heavyweight Championship.