Holding notable victories over Rumina Sato, Masakazu Imanari, Alexandre Franca Nogueira, Brad Pickett, Royler Gracie, Darren Uyenotama, and Yoshiro Maeda and possessing an exciting, grappling oriented style; Hideo Tokoro has been a mainstay in the Japanese MMA circuit since his debut at Titan Fighting Championship in 2000.

Tokoro, a natural flyweight, has shown a willingness to fight opponents much larger then him over the length of his career fighting as high as lightweight with success.  This willingness is typical of Japanese fighters and exemplifies the "warrior spirit" held in such high regard by Japanese fighters and fans.
 

He has participated in many MMA tournaments in several promotions. He participated in the K-1 Hero's 2005, 2006, and 2007 Lightweight Grand Prix's. He participated in the Dream Featherweight Grand Prix making it to the semifinals. He also participated in both of Dream's Bantamweight Grand Prix's. He won the first by defeating Yoshiro Maeda and Masakazu Imanari in the finals.

Since his Grand Prix victory, Tokoro has posted a 2-5 record over the past three and a half years. He was defeated by Antonio Banuelos at DREAM 17 via split decision and Yusup Saadulaev at DREAM: Fight for Japan. He evened those losses out with a pair of victories over Rumina Sato at Vale Tudo Japan 2012, winning via TKO; his second win came by way of a heel hook victory over Taylor McCorristan at Vale Tudo Japan: VTJ 2nd.

Tokoro has lost his last three fights since his win over McCorristan. He lost a split decision to Will Campuzano at Vale Tudo Japan: VTJ 3rd, was defeated via TKO by Victory Henry at Grandslam MMA: Way of the Cage, and lost again via split decision to LC Davis at Bellator 135 in what is considered an early candidate for Fight of the Year.