Meguro Manufacturing Co. Ltd., Tokyo, 1937-61
Tracing its history back to 1924 and the Murato Iron Works, Meguro was one of the first large scale Japanese motorcycle manufacturers, offering machines under its Meguro (メグロ号) brand. Pre WWII Meguro primarily made transmissions for other manufacturers (including Rikuo). They also produced a 500cc single called the Z97 which was patterned after the Swiss MAG engine in 1937, which remained in production till 1940. The Z97 was recognised as a landmark vehicle in Japanese design by the Society of Automotive Engineers of Japan, and you can read about it at this link.
Post WWII Meguro offered British styled single and twin 4 stroke engines in displacements ranging from 125cc through 650cc. In the late 1950's they had financial difficulty due to a year long labour disruption which led them to form a business relationship with Kawasaki who eventually took them over completely in 1964. The original Kawasaki W series of 625cc machines released in 1965, while being a Japanese design undoubtedly owed a lot to the derivative of the BSA A7 first made by Meguro (supposedly under licence although I have yet to see actual proof of this) in 1956.
Trivia fact: Even though Meguro disappeared as a brand in 1964, if you look at the original tool kits supplied with Kawasaki machines into the very early 1970's you will find the Meguro company logo on the open end wrenches.