Misaki (22-8-1) won a unanimous decision against Logan Clark at "Sengoku 3" in June. Misaki is expected to return to the promotion late 2008/early 2009 to face the winner of the "Sengoku" Middleweight GP for the promotion's first ever 183-pound title.
Misaki, who signed a two-fight deal in March to fight exclusively in North America with Strikeforce, will be making his promotional debut.
"Joe Riggs is a tremendous competitor. His style is aggressive like mine so I have no doubt that our fight will be an exciting and memorable one," Misaki said.
Riggs (28-10) is coming off a tune-up fight on July 26 at Rage in the Cage 112. Riggs says he has recovered 100 percent from a back injury that forced him to verbally submit at "Strikeforce at the Dome" in February. This will be Riggs' last fight as a middleweight, as he plans on venturing back into the welterweight division.