KO-D無差別級王座
Kudo returned to Japan and DDT on April 2, 2006, teaming with Mikami in a tag team match, where they defeated Harashima (the now unmasked Hero!) and Jet Shogo. During the following months, Kudo feuded with former partner Harashima and his villainous Disaster-Box stable. On June 25, Kudo teamed with Masami Morohashi and Seiya Morohashi in a six-man tag team match for the DDT Jiyugaoka Six-Person Tag Team Championship, losing to the team of Harashima, Muscle Sakai and Yusuke Inokuma. On July 2, Kudo, Mikami and Shiima Xion defeated Harashima, Toru Owashi and Yusuke Inokuma to win the 2006 Takechi Six Man Tag Scramble Cup. The rivalry culminated on July 23 in an eight-man elimination tag team match, where Kudo, Mitsuya Nagai, Poison Sawada Julie and Sanshiro Takagi, representing DDT, faced Harashima, Danshoku Dino, Jet Shogo and Toru Owashi, representing Disaster-Box. Kudo scored the final elimination of the match, pinning Harashima to give DDT the win over Disaster-Box. As a result, Kudo was granted a shot at Toru Owashi's KO-D Openweight Championship on August 27, but was unable to dethrone the defending champion. After returning from a short break following an injury, Kudo turned heel and formed the Team 2 Thousand Island stable with Sanshiro Takagi and Yoshiaki Yago, continuing his rivalry with the now-face Harashima. Kudo and Harashima faced off on November 23 in a grudge match, which was won by Harashima, who, as a result, became the number one contender to the KO-D Openweight Championship, which he went on to win from Toru Owashi a month later.