Tajiri was trained in traditional Japanese style and lucha libre, he debuted in the early 1990s in Japan wrestling mainly for the Japanese office of Consejo Mundial de Lucha Libre (CMLL). In 1997, he left for the hardcore wrestling promotion Big Japan based in Tokyo.
In late 1998, while in Mexico, he caught the eye of Extreme Championship Wrestling owner Paul Heyman and was invited to the United States to wrestle for ECW. He became extremely popular with the fans, despite being brought in as a heel. He had a long feud with Super Crazy that had several exciting matches.
He stayed in ECW until it closed in 2001, and was almost immediately signed by WWE, where he has been ever since. He started out as a face and later after the Alliance broke up he drafted to SmackDown! during the first ever draft and later turned heel by betraying his story line girlfriend, then SmacDdown! star and then babyface, Torrie Wilson and made her dress like a Geisha. Later Tajiri turned face again by getting betrayed by Jamie Noble. He was later in a match against his good friend Rey Mysterio. Mysterio won, but Tajiri turned heel once more and betrayed him by spitting green mist in his face. Later after WrestleMania 20 Tajiri was drafted to RAW and turned face once more by engaging in a rivarly with Eric Bishoff and Jonathan Coachman.
On February 4, 2005 Tajiri and William Regal defeated La Résistance to win the World Tag Team Championship on an episode of RAW broadcast live from Tajiri's home country of Japan. Since then, in addition to holding the titles, Tajiri has been allowed to showcase a more comedic side to his personality, appearing in many funny sketches along with Regal and other WWE stars.
La Résistance repeatedly attempted to regain the gold (mainly on Sunday Night Heat) from Regal and Tajiri in many different matches but just fell short during each one, during their "last shot" for the gold the team thought they had won back the titles only to have the decision reversed by referee Mike Chioda due to La Résistance not pinning the legal man. After this match Regal issued an open challenge to any tag team in the world to come after their belts, Jonathan Coachman showed a large interest to this announcement. On the following episode of RAW, Regal & Tajiri successfully defended the belts against the debuting Romeo and Antonio, known collectively as "The Heart Throbs."
On May 1, 2005, at Backlash, Regal & Tajiri participated in a "Tag-Team Turmoil" match in which four teams competed for the World tag team titles. Regal & Tajiri were eliminated by La Résistance who, in turn, were eliminated by Hurricane and Rosey, who became the new champions.
He appeared at the ECW One Night Stand pay-per-view, losing to Super Crazy.
Tajiri formed a tag team with another former tag partner of Regal's, Eugene for a while but the team did not last.
