Ishikari began 2005 by challenging for the World Junior Heavyweight Championship against champion Taka Michinoku in a losing effort, then continued wrestling in the lower mid-card.

On May 26, 2004, Taichi Ishikari appeared as a member of Team Japan in Total Nonstop Action Wrestling's 2004 World X Cup, competing in both a battle royal and a ladder match.

In mid 2006 Ishikari started to appear on New Japan Pro-Wrestling shows and his activity with the company then increased in 2006 and 2007 and finally in 2009 he became an official member of the NJPW roster.

[2] Taichi made his CMLL debut on February 19, 2010, in Arena México, Mexico City where he teamed up with Naito and Ray Mendoza, Jr. to defeat Strong Man, Mr. Niebla and Máximo in two straight falls.

[10] On May 7, 2010 Taichi and Okumura teamed up with former IWGP Heavyweight Champion Hiroshi Tanahashi to defeat El Hijo del Fantasma, La Máscara and Héctor Garza to win the CMLL World Trios Championship in the main event of the weekly Friday night Super Viernes show.

On December 11, 2010, Taichi returned from his latest stint in CMLL and aligned himself with IWGP Heavyweight Champion Satoshi Kojima as part of Kojima-gun, which would later also come to include MVP, Nosawa Rongai and Taka Michinoku.

[19] Since then, Taichi has formed a regular partnership with Taka Michinoku, with the two unsuccessfully challenging Prince Devitt and Ryusuke Taguchi for the IWGP Junior Heavyweight Tag Team Championship on September 11, 2011.

[23] On September 5, Taichi returned to Mexico for another tour with CMLL and instantly turned down an offer to rejoin La Ola Amarilla, pledging his loyalty to Minoru Suzuki and Suzuki-gun.

[24] In his first match back in CMLL on September 7, Taichi teamed with Hiroshi Tanahashi, Namajague and Okumura in a Japan vs. Mexico torneo cibernetico, where they faced Black Warrior, La Máscara, Negro Casas and Valiente.

[29][30][31] On May 24, Taichi entered the 2013 Best of the Super Juniors tournament, where he got off to a flying start, winning his first four matches, albeit through cheating, including interference from Taka Michinoku and locking Jyushin Thunder Liger out of the building for a countout victory.

[34] On July 20, Taichi and Michinoku received another shot at the IWGP Junior Heavyweight Tag Team Championship but were defeated by the defending champions, the Forever Hooligans (Alex Koslov and Rocky Romero).

[37][38] Back in New Japan on September 29 at Destruction, Taichi and Michinoku failed to earn another shot at the IWGP Junior Heavyweight Tag Team Championship, when they were defeated in a number one contender's match by Time Splitters (Alex Shelley and Kushida).

[44] Taichi was, however, later granted entry into the semifinals, after the block's winner, Alex Shelley, was forced to pull out of the tournament due to a shoulder injury.

[46] The following day, New Japan suspended Maki for two months with a 30% pay cut after photos of him having an extramarital affair started circulating, implying he cheated on his wife.

Taichi and El Desperado received a shot at the IWGP Junior Heavyweight Tag Team Championship on September 23 at Destruction in Okayama but were defeated by the Time Splitters.

[64] In March, Taichi entered the 2019 edition of the New Japan Cup, defeating Tomoaki Honma in the first round before being eliminated in the second by Tomohiro Ishii.

On January 4, he and other members of Suzuki-gun (Minoru Suzuki, Zack Sabre Jr., and El Desperado) defeated Los Ingobernables de Japón (EVIL, SANADA, Shingo Takagi, and BUSHI) in an eight-man tag team match.

[80] In October, Taichi competed in a tournament to crown the inaugural NJPW World Television Champion, but was defeated and eliminated by Sanada in the first round.

[82] Later in the month, at the World Tag League & Best of the Super Juniors finals, Minoru Suzuki announced the disbandment of Suzuki-gun by the end of the year.

[83] The final match between the faction took place on December 23, where the team of Taichi, Sabre Jr, Kanemaru and Douki defeated Suzuki, Archer, Desperado and Michinoku.

[84] Taichi started 2023, by competing in the New Japan Rambo, match on January 4 at Wrestle Kingdom 17, but failed to last till the final 4.

[85] The following day at New Year Dash, Taichi reunited with former Suzuki-gun stablemates, Yoshinobu Kanmaru, Taka Michinoku and Douki, forming anew stable called Just 4 Guys.

After the match, Just 4 Guys members (Taichi, Michinoku, Douki and Kanemaru) entered the ring, congratulating Sanada, causing the remainder of LIJ to come to ringside.

At the event, Taichi lost the title to Sho, in a seconds handcuffed match, after Yoshinobu Kanemaru turned on him and Just 5 Guys and joined House of Torture.

[96] On July 20, Taichi returned to NJPW to take part in the Super J-Cup, defeating AJPW's Yuma Aoyagi in his first round match.

[97] On August 21, Taichi defeated Jyushin Thunder Liger in the second round of the tournament, before being eliminated in the semifinals by reigning IWGP Junior Heavyweight Champion Kushida.