The .099 cuin (1.6 cc) displacement category was the smallest such category in which the manufacturers of the Mamiya model engines, Tokyo Hobbycrafts, chose to compete. It was also the most prolific, with no fewer than eight distinct models appearing during the approximately ten-year lifespan of the Mamiya range.

The general history of the Mamiya engines has been summarized in an article to be found elsewhere on this website. A detailed article focusing on the Mamiya .099 models may also be found here.