His return match took place on August 6, 2010, when he teamed up with El Samurai in a tag team match, where they were defeated by Hirooki Goto and Ryusuke Taguchi.[10] In the round robin stage of the tournament Kojima won five out his seven matches and won his block to advance to the finals, where, on August 15, he defeated Hiroshi Tanahashi to win G1 Climax.[11] On October 11 Kojima defeated Togi Makabe to win the IWGP Heavyweight Championship for the second time.[12] On December 11 Kojima made his first successful defense of the title, defeating Shinsuke Nakamura.[13] On December 14 Kojima announced that he was starting his own stable, tentatively named Kojima Office, and named Taichi, who had accompanied him to the ring for his Nakamura match, its first member.[14] Kojima turned heel on December 23, when he hit his number one contender Hiroshi Tanahashi with a lariat after a match, where he and Kota Ibushi had defeated Tanahashi and Prince Devitt.[15] On January 4, 2011, at Wrestle Kingdom V in Tokyo Dome, Kojima lost the IWGP Heavyweight Championship to Tanahashi.[16][17] On January 30 Kojima defeated Togi Makabe to earn a rematch with Tanahashi.[18] Meanwhile, the newly renamed Kojima-gun expanded to include Taka Michinoku and Nosawa Rongai, who in turn used his connections to get MVP to also join the group.[19][20] Kojima received his rematch for the IWGP Heavyweight Championship on February 20 at The New Beginning, but was again defeated by Tanahashi.[21] After Kojima was defeated by Togi Makabe on May 3, Taichi and Taka Michinoku turned on him and named the returning Minoru Suzuki as their new leader, while Kojima himself formed a new partnership with Makabe and MVP, who left the stable after Suzuki took over.[22][23][24] On July 18, Suzuki defeated Kojima in a singles match.[25] The two had a rematch on August 1 during the first day of the 2011 G1 Climax, where Kojima managed to pick up the win.[26] Kojima managed to win five more matches in the tournament, but a loss to former partner Hiroyoshi Tenzan on the final day eliminated him from the running for a spot in the finals.[27] After the tournament Kojima was sidelined indefinitely with an eye injury suffered during the match with Tenzan.[28]