He is also known for his year-long excursion to the United States, during which he performed for promotions such as Chikara, Dragon Gate USA, and Pro Wrestling Guerrilla.

[6] On July 11, 2008, after having teamed with Ono for a little over half a year, he appeared on a show with his gakuran pants on and announced that, in light of the success that new stablemates Shinobu and El Generico had brought to the unit (as well as constant pestering from Iwasa and Arai), he was going on a diet.

After a diet trial series, where he actually had success, he brashly challenged Open the Triangle Gate Champions Masaaki Mochizuki, Don Fujii, and Magnitude Kishiwada to a title match against him, Iwasa & Arai on November 16.

[24] On March 4, 2011, Tozawa and Kevin Steen, dubbing themselves the Nightmare Violence Connection, entered PWG's DDT4 tournament, upsetting the Briscoe Brothers in their first round match.

After another upset victory over the ROH World Tag Team Champions, The Kings of Wrestling (Chris Hero and Claudio Castagnoli), he and Steen made it to the finals of the tournament, where they were defeated by The Young Bucks (Matt and Nick Jackson).

[26] On April 15, Tozawa returned to Chikara, captaining Team Dragon Gate, consisting of himself, Kagetora and Super Shisa, in the 2011 King of Trios tournament.

[13][27] The following day, Team Dragon Gate was eliminated from the tournament in the quarterfinal stage by The Osirian Portal (Amasis, Hieracon and Ophidian).

[29] On April 19, Tozawa made his debut for Evolve at the promotion's first live internet pay-per-view, facing Chuck Taylor in a losing effort.

During the first night of All Star Weekend 8, Tozawa and Kevin Steen defeated El Generico and Ricochet in a tag team match.

[33] On June 3, Tozawa and Yamato failed to capture the Open the United Gate Championship when they lost to reigning champions Masato Yoshino and Pac at Fearless 2011.

[35] Tozawa received another shot at the title on July 28, 2013, at Dragon Gate USA's fourth anniversary event, but was again defeated by Gargano.

[40] In August, Tozawa and fellow Blood Warriors member BxB Hulk took part in the 2011 Summer Adventure Tag League, where they ultimately defeated Masaaki Mochizuki and Yamato of rival group Junction Three to win the tournament.

[46] On February 9, the Tozawa-led Blood Warriors won their feud with Junction Three by defeating them in a fourteen-man elimination tag team match, forcing their rival group to disband.

[50] On August 19, Tozawa, BxB Hulk and Naoki Tanisaki defeated Cima, Gamma and Magnitude Kishiwada to win the 2012 Summer Adventure Tag League and the vacant Open the Triangle Gate Championship.

[52] On May 5, 2013, Tozawa received another shot at the Open the Dream Gate Championship in the main event of Dead or Alive 2013, but was again defeated by Cima.

[63] On November 1, Tozawa lost the Open the Brave Gate Championship to Kotoka in a three-way match, which also involved Naoki Tanizaki.

On September 25, he announced that he would be wrestling his final Dragon Gate match on November 3, before moving to the United States to work for WWE.

In February 2018, Tozawa formed a tag team with Hideo Itami, and they defeated Gran Metalik and Lince Dorado on the March 13 episode of 205 Live, but got into a confrontation with them and their ally Kalisto post-match.

After trading victories between each other, they finally lost a tornado tag team match to Metalik and Dorado on the April 17 episode of 205 Live after Tozawa accidentally kicked Itami.

On the January 2, 2019, episode of 205 Live, Tozawa defeated Drew Gulak to qualify for the fatal four-way match at Royal Rumble for the Cruiserweight Championship, which was won by champion Buddy Murphy.

[75][76] On the December 23 episode of Raw, Tozawa captured the 24/7 Championship after pinning champion R-Truth, but lost the title to Santa Claus.

[79] At Backlash, during a segment between The Street Profits and The Viking Raiders, Tozawa appeared with a gang of ninjas on motorcycles, turning heel.

[80] On the June 22 episode of Raw, Tozawa defeated R-Truth to become the 24/7 Champion for the second time, only to lose the title back to Truth one week later.

[81] On the August 3 episode of Monday Night Raw, Tozawa won the 24/7 Championship for a third time in a triple threat match against champion Shelton Benjamin and R-Truth.

On the February 15 episode of Raw, he pinned R-Truth backstage to win the 24/7 Championship but lost it to Bad Bunny after being attacked by Damian Priest, ending his reign at 28 seconds.

When Reggie won the title after he was abandoned by Nia Jax and Shayna Baszler, he and R-Truth began feuding with him, even building a temporary alliance with Drake Maverick.

Tozawa joined Alpha Academy and was assigned as a "junior member" of the stable in a Digital Exclusive before the October 23, 2023, episode of Raw.

On the July 15 episode of Raw, Otis, Dupri and Tozawa agreed to team up with The New Day's Xavier Woods in his feud against The Final Testament.

After the match, Gable, together with the newly-aligned Creed Brothers (Julius and Brutus), continued to convince Otis, Tozawa and Dupri to reunite.