He followed up a 10–5 record in March with a 12–3 score and runner-up honours in May (his first "jun-yusho" in over two years), with the Sumo Association's chairman Kitanoumi indicating that 12 wins in the following tournament would be enough to clinch "ōzeki" promotion. In July 2007 Kotomitsuki produced a 13–2 score, defeating west "yokozuna" Hakuhō and once again finishing runner-up, this time to east "yokozuna" Asashōryū. He lost to Kisenosato on the final day, missing the chance of a playoff for the championship with Asashōryū and the first "yūshō" for a Japanese born wrestler since January 2006. Kotomitsuki's "ōzeki" promotion, confirmed on 25 July 2007, was of special significance to Kotomitsuki and the Sadogatake-beya. Having missed qualifying in 2002 due to a combination of injuries and bad timing, Kotomitsuki was seen by detractors as having insufficient will and being slightly advanced in age to attain "ōzeki" status. For comparison, Tochiazuma who reached "ōzeki" in 2002 is Kotomitsuki's junior by 7 months. At the age of 31 years 3 months, Kotomitsuki proved the naysayers wrong, becoming the oldest wrestler to attain the rank in the modern era. Kotomitsuki scored a respectable ten wins on his "ōzeki" debut in September 2007, but at the end of 2007 he underwent surgery to remove gallstones. He was not at his best in the 2008 New Year tournament but won his eighth bout on the final day to achieve a "kachi-koshi" or winning score. He produced another unremarkable 8–7 mark in March, but did manage to end his 28 consecutive defeats against his nemesis Asashōryū. In July 2008, in his "home" tournament in Nagoya, he finished as runner-up to Hakuhō on 11–4, the eighth and final time in his career he was a tournament runner-up (and his only as an "ōzeki"). He matched this score in September, although he finished in third place behind Hakuhō and Ama. Entering the January 2009 tournament with a gout problem in his right ankle, Kotomitsuki took his first "make-koshi" or losing record as an "ōzeki", breaking a run of twenty consecutive "kachi-koshi" scores.