is a Japanese mixed martial artist. He fought for the Tokyo Sabres in the International Fight League.
Hamanaka began his mixed martial arts career in 2003 with a victory over Antonio Schembri at PRIDE 26. After losing to Ryan Gracie in PRIDE Bushido 1, he made stints in other organizations such as K-1. Over his mixed martial arts career, Hamanaka has trained with IFL coaches Matt Lindland and Dan Henderson, as well as UFC legend Randy Couture. Kazuhiro currently resides in Tokyo.
|- | Loss | align=center| 5âÂÂ7âÂÂ1 | Shunsuke Inoue | TKO (punches) | | | align=center| 1 | align=center| 0:52 | Tokyo, Japan | |- | Win | align=center| 5âÂÂ6âÂÂ1 | Alavutdin Gadjiev | DQ (illegal knee) | GCM - Cage Force & Valkyrie | | align=center| 3 | align=center| 1:04 | Tokyo, Japan | |- | Loss | align=center| 4âÂÂ6âÂÂ1 | Karl Amoussou | KO (flying knee) | | | align=center| 1 | align=center| 0:23 | Tokyo, Japan | |- | Loss | align=center| 4âÂÂ5âÂÂ1 | Matt Horwich | KO (head kick) | IFL-Everett | | align=center| 1 | align=center| 2:07 | Everett, Washington, United States | |- | Loss | align=center| 4âÂÂ4âÂÂ1 | Jeremy Williams | TKO (triangle choke) | IFL-Los Angeles | | align=center| 1 | align=center| 0:59 | Los Angeles, California, United States | |- | Loss | align=center| 4âÂÂ3âÂÂ1 | Alex Schoenauer | Submission (guillotine choke) | IFL-Portland | | align=center| 1 | align=center| 1:04 | Portland, Oregon, United States | |- | Win | align=center| 4âÂÂ2âÂÂ1 | Yoichi Babaguchi | Submission (kimura) | Hero's 5 | | align=center| 1 | align=center| 1:22 | Tokyo, Japan | |- | Win | align=center| 3âÂÂ2âÂÂ1 | Wesley Correira | Submission (kimura) | ROTR 9-Rumble on the Rock 9 | | align=center| 2 | align=center| 1:53 | Honolulu, Hawaii, United States | |- | Loss | align=center| 2âÂÂ2âÂÂ1 | Wilson Gouveia | TKO (punches) | Euphoria-USA vs. Japan | | align=center| 1 | align=center| 0:39 | Atlantic City, New Jersey, United States | |- | Draw | align=center| 2âÂÂ1âÂÂ1 | Yukiya Naito | Draw | GCM-D.O.G. 3 | | align=center| 2 | align=center| 5:00 | Tokyo, Japan | |- | Win | align=center| 2âÂÂ1 | Webster Dauphiney | KO | NJPW-Los Angeles Dojo Show | | align=center| 2 | align=center| 0:40 | Los Angeles, California, United States | |- | Loss | align=center| 1âÂÂ1 | Ryan Gracie | TKO (soccer kicks) | PRIDE Bushido 1 | | align=center| 1 | align=center| 7:37 | Saitama, Japan | |- | Win | align=center| 1âÂÂ0 | Nino Schembri | Decision (unanimous) | PRIDE 26 | | align=center| 3 | align=center| 5:00 | Yokohama, Japan |