NEVER無差別級王座
On May 3, 2013, Naito made an appearance at New Japan's Wrestling Dontaku 2013 event, announcing that he would be returning to the ring on June 22, while also naming the NEVER Openweight Championship, held by Masato Tanaka, as his goal. On June 22 at Dominion 6.22, Naito defeated Takahashi in his return match. On July 20, Naito failed in his attempt to capture the NEVER Openweight Championship from Tanaka. From August 1 to 11, Naito took part in the 2013 G1 Climax. Finishing with a record of five wins and four losses, Naito clinched the number one spot in his block and advanced to the finals after a win over Karl Anderson on the final day. In the finals, Naito defeated Hiroshi Tanahashi to win the 2013 G1 Climax and earn a shot at the IWGP Heavyweight Championship. Naito, however, announced that he first wanted a rematch with Masato Tanaka for the NEVER Openweight Championship. The following day, Naito was given a contract, which granted him a shot at the IWGP Heavyweight Championship on January 4, 2014, at the Tokyo Dome. On September 29 at Destruction, Naito defeated Masato Tanaka to not only retain the contract, but to also win the NEVER Openweight Championship. On October 14 at King of Pro-Wrestling, Naito successfully defended both the title and the contract against Yujiro Takahashi. On November 9 at Power Struggle, Naito defeated Masato Tanaka to retain the NEVER Openweight Championship and solidify his spot in the main event of the January 4 Tokyo Dome show. Naito and reigning IWGP Heavyweight Champion Kazuchika Okada faced off on November 23 during the first day of the 2013 World Tag League in a match, where Naito and Mexican wrestler La Sombra were defeated by Okada and Yoshi-Hashi. Naito and La Sombra finished the tournament on December 6 with a record of three wins and three losses, failing to advance from their block. Following a disappointing fan reaction to a confrontation between Naito and Okada, New Japan announced that fans would get to vote whether they or Shinsuke Nakamura and Hiroshi Tanahashi for the IWGP Intercontinental Championship would be the true main event of the Tokyo Dome show. When the results were released on December 9, Naito and Okada had gotten only half the votes Nakamura and Tanahashi had gotten and, as a result, lost their main event spot for New Japan's biggest show of the year. On January 4, 2014, at Wrestle Kingdom 8 in Tokyo Dome, Naito failed in his title challenge against Okada. The following day, Naito entered a new feud with Tomohiro Ishii, who announced his intention of becoming the next NEVER Openweight Champion. On February 11 at The New Beginning in Osaka, Naito lost the NEVER Openweight Championship to Ishii in his third title defense.