Kenta made his surprise debut for New Japan Pro-Wrestling (NJPW) on June 9, 2019 at the Dominion 6.9 in Osaka-jo Hall event as a face, with Katsuyori Shibata as his manager, announcing his participation in the 2019 G1 Climax tournament. Kenta made his in-ring debut for NJPW on July 6, defeating Kota Ibushi as a part of the tournament. Kenta, competing in the A Block of the tournament, stayed undefeated in singles matches for over a month and a half, defeating Hiroshi Tanahashi, Lance Archer, and Evil before suffering his first defeat against IWGP Heavyweight Champion Kazuchika Okada on July 27, as part of the tournament. Kenta would then lose his next four matches against Sanada, Bad Luck Fale, Will Ospreay and Zack Sabre Jr., failing to win the tournament with a final tally of 8 points (four wins and five losses).