from the sport, beating Takaku Fuke by ankle lock in the first round at a U-SPIRITS event. Professional wrestling career Battlarts (1999–2000) Nagai turned his hand to professional wrestling and joined Yuki Ishikawa's shoot style promotion Battlarts. His run was somewhat successful, with Nagai earning victories over established wrestlers like Takeshi Ono, Yuki Ishikawa and Katsumi Usuda. In the 2000 Young Generation Battle, Nagai went undefeated for the entirety of the tournament, beating Usuda, Mohammed Yone, Mach Junji, Rastaman and Minoru Tanaka to reach the final, where he lost to Alexander Otsuka. After Battlarts went on hiatus beginning in November 2000, Nagai and the rest of the roster were forced to leave the promotion. All Japan Pro Wrestling (2001–2005) Almost immediately after Battlarts began its hiatus, Nagai was announced for the 2000 Real World Tag League in All Japan Pro Wrestling (AJPW), the promotion he had originally hoped to join in high school. Nagai was paired up with fellow UWF alumnus Masahito Kakihara, calling themselves "Team Strongs". Despite the name, Team Strongs performed poorly in the tag league, earning just two points with a win over Barry Windham and Kendall Windham. In only his second match, Nagai lost to AJPW's top star Toshiaki Kawada, and, even though he lost, he earned Kawada's respect and was selected to be his new tag partner. As a newcomer, Nagai was required to prove himself before he entered the 2001 Champion Carnival, and thus was put into the Champion Carnival Qualifying League. Nagai excelled in the qualification league which granted him entry to the Champion Carnival where he struggled, again earning just one win and two points. Despite mixed success and his newcomer status, Nagai was pushed as an All Japan loyalist and represented the company in interpromotional matches during AJPW's working relationship with New Japan Pro-Wrestling (NJPW). On June 6, 2001, Nagai was involved in an incident during a match against NJPW wrestler Takashi Iizuka at an NJPW show, where Nagai delivered a kick to Iizuka's face which resulted in Iizuka being severely concussed and needing over a year off to recover. Two days later when the NJPW roster came to the AJPW show in Nippon Budokan, Nagai and Kakihara beat NJPW's Yuji Nagata and Shinya Makabe to win the vacant All Asia Tag Team Championship, however, their reign was cut short after Kakihara suffered a knee injury and eventually left All Japan