Rizin World Grand Prix 2015: Part 1 - Saraba was an inaugural mixed martial arts event held by the Rizin Fighting Federation on December 29, 2015 at the Saitama Super Arena in Saitama, Japan .

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.

DREAM.11 took place on October 6, 2009, at Yokohama Arena in Yokohama, Japan, promoted by Fighting and Entertainment Group’s DREAM. The main event features Shinya Aoki vs. Joachim Hansen for the Lightweight Championship, where Aoki seeks to reclaim the title after losing to Hansen in 2008, and Kazushi Sakuraba vs. Rubin Williams in a middleweight clash.

DREAM.8 took place on April 5, 2009, at Nippon Gaishi Hall in Nagoya, Japan, promoted by Fighting and Entertainment Group’s DREAM. The main event features Hayato "Mach" Sakurai facing Shinya Aoki in a welterweight Grand Prix opening round bout, with Sakurai coming off a TKO win over Kuniyoshi Hironaka at DREAM.6 and Aoki fresh from a submission victory over David Gardner at DREAM.7. Other welterweight Grand Prix matchups include Marius Žaromskis vs. Seichi Ikemoto, Jason High vs. Yuya Shirai, and Andre Galvão vs. John Alessio. Additional bouts showcase Sergei Kharitonov vs. Jeff Monson in a heavyweight clash and Riki Fukuda vs. Murilo Rua.