Dream 12 was a mixed martial arts event promoted by Fighting and Entertainment Group's mixed martial arts promotion Dream that took place on October 25, 2009 in Osaka, Japan. The event marked the first time Dream used a hexagon cage. Fights consisted of three five-minute rounds, as used in the North American system, though elbows remained illegal.
On August 12, 2009, it was announced the event would take place October 25 at the Osaka Castle Hall in Osaka, Japan. Dream's EP Sasahara hinted at a "big surprise" which he said had a 70% chance of actually happening. This "big surprise" turn out to be the introduction of a cage as Dream's fighting platform.
Prior to Dream 12, Dream utilized their official YouTube channel to provide hype for the event. On August 21, 2009, a brief promotional video teasing viewers with the first appearance of a cage was uploaded. A month later, on September 23, 2009, another Dream 12 promotional video was uploaded, this time depicting potential participants intertwined with footage showing the construction of Dream's white cage. The show, Event Producer Seiichi Sasahara said Sakuraba could potentially fight again later in the month, though no official decision has yet to be made. A week out from the event, Sakuraba was confirmed for Dream 12.