Starting in the early 1960’s, Masaharu Okazaki set out on a mission to build high-performance Japanese race engines to compete with the championship-winning European offerings of the time. Armed only with a pure passion for motorsports and an innate ability to absorb information, he basically took things apart in his garage, figured out how they work, and designed improvements to increase performance. A self-educated man, he originally began working on motorcycles and eventually moved on to parts development for 4-wheel automobiles. Mr. Okazaki founded his company, OS Giken, in the early 1970’s with strength, durability, and the pursuit of high performance in mind; these goals for parts development remain true today and OS Giken has established itself in the upper-echelon for designing and manufacturing high quality, high performance, and supremely durable parts.

From Mr. Okazaki’s humble beginnings tinkering with motorcycle parts at home, OS Giken has evolved and grown over the years, building and cementing a reputation as one of the best racing drivetrain parts manufacturers in the world. Officially founded in 1973, the company headquarters and factory are located in Okayama, Japan. All OS Giken parts are 100% manufactured and assembled in Japan, under very strict quality-control guidelines. Production and design capabilities for engine and drivetrain components are OS Giken’s specialty, but the company has the ability to design and build just about anything mechanical. As the design, construction, and usage of the automobile evolves, OS Giken looks forward to the challenges presented to find room for improvement!