On December 14, 2002, Mishima challenged
Takanori Gomi for the Shooto welterweight (154 lb) championship, but lost by
technical knockout due to punches. On February 12, 2005, Mishima was victorious against fellow DEEP veteran
Tomomi Iwama becoming the first lightweight (155 lb) champion of the organisation. However, Mishima didn't defend his belt and returned it one year later. Mishima had four fights in
PRIDE, winning over
Charles Bennett and
Marcus Aurélio and losing to
Yves Edwards and
Ralph Gracie. His final appearance with the company was in the reserve fight of
PRIDE Bushido 9 on September 25, 2005, where he defeated fellow alternate Charles Bennett with an
ankle lock. On November 18, 2006, Mishima made his debut in the U.S. at
UFC 65.
Joe Stevenson, the winner of
The Ultimate Fighter 2 who had just moved down to the lightweight division (155 lb), defeated Mishima in the first round by a
guillotine choke. Mishima's fought
Kenny Florian at
UFC Fight Night 9 on April 5, 2007, in
Las Vegas. Mishima lost to a
rear naked choke, shortly after attempting to submit Florian with a
knee bar. On May 19, 2008, Mishima dropped to
featherweight (145 lb) to fight
Masakazu Imanari. Mishima won by unanimous decision, becoming the
DEEP featherweight champion. He also became the first man to capture the DEEP belt in two different divisions. ==Championships and accomplishments==