Kamitani made his
professional wrestling debut in
Big Japan Pro Wrestling (BJW) at a promotion's
house show held on April 4, 2012, where he defeated Masashi Otani in an
exhibition match.[6] He would often participate at cross-over events held between Big Japan Pro Wrestling,
Dramatic Dream Team (DDT) and
Kaientai Dojo (K-Dojo) such as the New Year's Eve Toshikoshi Pro-Wrestling 2012 from December 31, where he teamed up with Tank Nagai and FUMA in a losing effort to
Daisuke Sekimoto,
Shuji Ishikawa and
Yuji Hino.[7] Another event of this kind was the BJW/CZW CZW Arena In Japan ~ BJW For MASADA from January 5, 2014, held in partnership with
Combat Zone Wrestling (CZW), where he teamed up with Takayuki Ueki, scoring a defeat against
Kazuki Hashimoto and Ryuichi Kawakami.[8] At BJW Ryogokutan 2016 on July 24, Kamitani defeated
Yuji Okabayashi to win the
BJW World Strong Heavyweight Championship.[9] Kamitani worked at BJW/ZERO1 Clash, a cross-over event held by BJW in partnership with
Pro Wrestling Zero1 on October 30, 2020, where he teamed up with Ryuichi Kawakami in a losing effort to Drew Parker and
Masato Tanaka.[10]
Kamitani made notable appearances in the Ikkitousen Strong Climb tournaments, competing for the first time in the
2014 edition of the event, placing himself in the Block A and going against Shuji Ishikawa,
Shinya Ishikawa,
Yuko Miyamoto,
Atsushi Maruyama and
Shiori Asahi, finishing with no points.[11] At the
2016 edition, he occupied a place in the Block A and competed against
Daichi Hashimoto, Daisuke Sekimoto,
Kohei Sato,
Seiya Sanada and Atsushi Maruyama, scoring a total of six points and advancing to the finals where he got defeated by Shuji Ishikawa.[12] Another popular event in which he participated was the
Saikyo Tag League, where at the
2014 edition, he teamed up with Daisuke Sekimoto, placing themselves in the Strong Style Block, where they obtained a total of eight points after facing the teams of
Koji Kanemoto and Kazuki Hashimoto,
Manabu Soya and Ryuichi Kawakami, Shuji Ishikawa and Kohei Sato, Shiori Asahi and
Shinobu, and Speed Of Sounds (
Tsutomu Oosugi and
Hercules Senga). They made it to the semi-finals where they lost against
Ryuji Ito and
Abdullah Kobayashi.[13] His best performance was at the
2017 edition, where he teamed up with Daichi Hashimoto, scoring six points in the Strong Style Block where they went against the teams of
Shingo Takagi and Yuji Okabayashi, Ryuichi Kawakami and
Yoshihisa Uto,
Ryota Hama and
Yasufumi Nakanoue,
Hideki Suzuki and
Shogun Okamoto, and Daisuke Sekimoto and Kohei Sato who they defeated in the semi-finals, and finally Abdullah Kobayashi and Ryuji Ito who they defeated in the finals to win the league.[14]
Kamitani participated in the wXw World Tag Team League 2018, an event promoted by
Westside Xtreme Wrestling (wXw) from October 5 to 7, where he teamed up with his usual tag partner Daichi Hashimoto as Okami, placing themselves in the Block A and competing against
Lucha Brothers (
Penta El Zero M and
Rey Fenix) in a losing effort on the first night.[19] On the second night, they pulled out a victory against Calamari Catch Kings (
Chris Brookes and
Jonathan Gresham).[20] They finished the tournament scoring a total of three points after they got defeated by Ringkampf (
Timothy Thatcher and
Walter) on the last night.[21]