I must thank my friend Streetracker for discovering this Japanese promotional film of the Meguro Rex-Y 350cc on You Tube. I've been looking for this film clip for ages.
The origins of the Meguro Works can be traced back to 1909, but the Meguro brand name does not appear until 1927. The company had begun to build motorcycles from sourced parts around 1922 and produced their first complete motorcycle in 1937 leading to major contracts to supply motorcycles to the Japanese Army and Police in 1939.
Motorcycle production was halted in 1941 when the Meguro Works was commandeered for the war effort and full production did not resume again until 1949. By the mid 1950s they were just about the biggest motorcycle manufacturer in Japan, producing 4-stroke singles and twins based quite closely on British and German designs, but financial difficulties forced Meguro into a business partnership with the Kawasaki Aircraft Company in 1960, leading to a full merger in 1963 and the formation of Kawasaki Auto Sales (the forerunner of the Kawasaki Motorcycle Company). Some of the first Kawasaki motorcycles were simply re-badged Meguro models and the Meguro logo actually formed part of the Kawasaki Motorcycles logo for many years after. Even today, the Kawasaki W650 model can trace its ancestry back to the Meguro K1 models from the late 1950s.
The best bit comes right at the end of the film though. There was once a time, pre Autorace and its regulation tarmac ovals, when the Japanese enjoyed dirt-track and speedway racing on tracks made from compacted volcanic ash. The Meguro single was the engine of choice for many Japanese riders at that time and here is some cinematic evidence of those oriental "go fast - turn left" race meetings. Check out their race suits, the big shoulder pads and goggles make them look like motorcycling Samurai... This is a fantastic piece of Japanese motorcycle history.