Arashi entered the Real World Tag League but they failed to advance in the tournament. On December 27, Muto made a return to the United States, wrestling for the Ring of Honor promotion as part of an interpromotional All Japan vs. ROH card, which hosted a series of cross-promotional "dream" matches. In the main event, Muto reverted to his Great Muta persona and teamed with Arashi to defeat Prophecy members Christopher Daniels and Dan Maff. Muto and Arashi finally lost the tag titles to Kaz Hayashi and Satoshi Kojima on January 18, 2004. Muto would then support AJPW in its feud with Roughly Obsess and Destroy and spent most part of the fall of 2003 and 2004 by competing in several matches against RO&D members. Muto found success in 2004 by entering that year's Champion Carnival, which he won by defeating Takao Omori in the semi-final and Kensuke Sasaki in the final on April 20. Muto picked up a major win against Osamu Nishimura at Battle Banquet. In November, Muto teamed with Nishimura to participate in the 2004 Real World Tag League but could not advance in their block. In 2005, Muto defeated his pupil Hiroshi Tanahashi of NJPW at Realize. On July 26, Muto received a title shot against Satoshi Kojima for the Triple Crown Heavyweight Championship but failed to win the title. While continuing to feud with RO&D, Muto and his supporters from the AJPW roster also began feuding with the Voodoo Murders. In November, Muto teamed with Akebono as they entered the 2005 Real World Tag League, making it to the final against Team 3D, which they lost. On March 10, 2006, Muto revived his Great Muta moniker as he unsuccessfully challenged Satoshi Kojima for the Triple Crown Heavyweight Championship. Muto failed in the 2006 Champion Carnival and continued his feud with Voodoo Murders throughout the year. At the end of the year, Muto was paired with Toshiaki Kawada in the 2006 Real World Tag League, where they tied Satoshi Kojima and Hiroyoshi Tenzan with eight points in the round robin stage, which led to a match between the two teams on December 2 to determine the final round opponents for the top-ranked team in the tournament, RO'Z and Suwama. Muto and Kawada lost their match. On December 15, Muto teamed with Kannazuki to defeat Hiroyoshi Tenzan and Akimasa Haraguchi to become the inaugural F-1 Tag Team