Yamamoto first worked for New Japan Pro Wrestling. He began his career there near the end of 1990, by fighting in a 32-man battle royal. Tenzan then went to the Catch Wrestling Association in Austria, where, wrestling under his real name, he defeated Lance Storm to become CWA World Junior Heavyweight Champion. A few weeks later, he lost to Storm, then came back in October 1993 to win the belt for the second time. Once again, Storm defeated him a few weeks later, and Tenzan headed back to the NJPW. Tenzan then began teaming with Masahiro Chono as Chono Team Wolf. In June 1995, Tenzan and Chono won the IWGP World Tag Team Championship in a tournament, which they held for a month until the title was vacated due to Chono missing a match when his father died.
Tenzan had a brief tenure in WCW and At Starrcade 1995, he was defeated by "Macho Man" Randy Savage.
In July 1996, Tenzan and Chono won the IWGP Tag-Team titles again, this time beating Kazuo Yamazaki and Takashi Iizuka. They held the titles for over 5 months before losing to Tatsumi Fujinami and Kengo Kimura. A few weeks later, Tenzan and Chono became founding members of nWo Japan. For the rest of 1997, Tenzan and the rest of nWo Japan continued the nWo tradition of attacking their various enemies.
Tenzan got his third chance for the IWGP Tag-Team Titles in July 1998, after Chono's former tag-team partner Keiji Mutoh was injured. Tenzan and Chono went on to win the tournament and the belts. A month later, they were defeated by Genichiro Tenryu and Shiro Koshinaka. Tenzan continued to feud with Koshinaka, eventually getting a new partner in Satoshi Kojima. The two teams fought at the Tokyo Dome in January 1999, with Tenzan & Kojima coming through, defeating Koshinaka & Tenryu to get the IWGP Tag-Team belts. A few months later, Koshinaka retook the titles from Tenzan & Kojima, with his partner Kensuke Sasaki. For the next year, Tenzan continued to wrestle in NJPW, feuding with Koshinaka, Masa Chono, Manabu Nakanishi, and others. He defeated Chris Benoit at the Tokyo Dome in January 2000.
In July 2000, Tenzan, still teamed with Kojima, got the IWGP Tag-Team Titles for the 5th time, winning over Manabu Nakanishi and Yuji Nagata. Tenzan & Sasaki feuded with Nakanishi & Nagata for the next few months, with Tenzan & Sasaki coming out on top.
On February 24, 2002 Tenzan made a brief appearance at WWA The Revolution pay-per-view from Las Vegas, Nevada where he choked Disco Inferno. Scott Steiner then attacked Disco in the ring. Tenzan could be seen sitting right behind the announcer's table when Disco joined commentary. He can be seen leaving the arena following Steiner's attack on Disco.
Tenzan also won the IWGP Tag Team Titles in March 2002 with Masahiro Chono (their title reign lasting over one year; it also tied the team record for most championships won with Fujinami & Kimura), and again in December 2003 with Osamu Nishimura.
In November 2003, Tenzan finally won the IWGP Heavyweight Title from Yoshihiro Takayama. He proceeded to win it three other times (in February 2004 from Genichiro Tenryu, December 2004 from Kensuke Sasaki and May 2005 from Satoshi Kojima).
He lost the championship to Kojima in a cross-promotional champion vs. champion match. Kojima held the AJPW Triple Crown Championship. The match ended when Tenzan was unable to get up, Kojima thus winning by a knock out. Tenzan got heat with the management of NJPW due to this, because he gave NJPW's most prestigious championship's control to the rival company, AJPW. This supports the speculation that the match didn't end the way it was booked to, and that Tenzan was really unable to get up and finish the match. Tenzan defeated Kojima in a rematch three months later, bringing the championship back to NJPW. He lost the championship to Kazuyuki Fujita on July 18, 2005.
Tenzan competed in the 2005 G1 Tournament, and almost made it to the semi-finals. in October 2005 Tenzan and Chono reunited to win the IWGP tag team title for a fifth time from Hiroshi Tanahashi and Shinsuke Nakamura.
On August 13, 2006 Tenzan defeated long time rival Satoshi Kojima in the final of the G-1 Climax, becoming only the second wrestler to go undefeated in a round robin style G-1. This would be his third G-1 title.
After severing ties with his old mentor Masahiro Chono, Tenzan founded the heel unit GBH ("Great Bash Heel", affectionatley referred to by fans as "Great Big Head"); it is composed of Tenzan, Togi Makabe, Shiro Koshinaka, Toru Yano, Tomohiro Ishii and Tomoaki Honma.
Speculation has been rampant since December about Tenzan's future in New Japan, and he still has yet to have formal contract talks with NJPW during their annual contract signings.
- Finishing and signature moves
- Tag teams and stables