DREAM.15 took place on July 10, 2010, at Saitama Super Arena in Saitama, Japan, promoted by Fighting and Entertainment Group’s DREAM. The main event features Shinya Aoki defending his Lightweight Championship against Tatsuya Kawajiri, with Aoki coming off a submission win over Mizuto Hirota at Dynamite!! 2009 and Kawajiri riding a TKO victory over Kazunori Yokota. Key undercard bouts include Gegard Mousasi vs. Jake O’Brien and Tatsuya Mizuno vs. Melvin Manhoef in the Light Heavyweight Grand Prix opening round, alongside Michihiro Omigawa vs. Cole Escovedo. Originally planned as an eight-man tournament, the Grand Prix was scaled back to four fighters.