Takagi made his surprise debut for New Japan Pro-Wrestling (NJPW) during the King of Pro-Wrestling event on October 8, 2018, joining the "Los Ingobernables de Japon" ("LIJ") faction. At Wrestle Kingdom 13 on January 4, 2019, Takagi teamed with Bushi to win the IWGP Junior Heavyweight Tag Team Championship from Suzuki-gun (Yoshinobu Kanemaru and El Desperado). However, Takagi and Bushi later lost the tag team championship to Roppongi 3K (Sho and Yoh) at NJPW's 47th Anniversary Show on March 6. At the G1 Supercard on April 6, Takagi competed in the Honor Rumble, but the match was won by Kenny King.