Debuting for Toryumon at the age of 16, he joined NJPW in August of 2007. After training overseas he returned in 2012 to compete in Wrestle Kingdom VI at the Tokyo Dome, where he joined CHAOS. The following month he defeated Hiroshi Tanahashi to win the IWGP Heavyweight belt in a moment known as the ‘Rainmaker Shock’.

Okada would go on to become the most decorated IWGP Heavyweight Champion in history, with a record 30 defences across his five reigns and a combined 1790 days as champion, including a 720 day, 12 defence reign between 2016 and 2018, itself a record. The IWGP Heavyweight Championship would evolve into the World Heavyweight Championship in spring of 2021, and that summer Okada would win the G1 Climax to eventually challenge for the newer title at Wrestle Kingdom, defeating Shingo Takagi to claim the gold on January 4 2022. 

Okada continued to lead NJPW through its 50th anniversary year with defences against Will Ospreay and Zack Sabre Jr., and a pair of wins over Tetsuya Naito. Yet his reign would crash to a halt at the hands of Switchblade Jay White, who planted Okada with a Bladerunner to capture the title on June 12 2022 at Dominion. Rebuilding with a dominant G1 Climax 32 victory, he regained the world title on January 4 2023, becoming the first two time holder of the IWGP World Heavyweight Championship, but his reign would crash to a halt at the hands of SANADA at Sakura Genesis 2023.