The Hamada was one of very few Japanese military weapons made by a private commercial firm. Designed and introduced in 1940, the basic Type Hamada pistol was a blowback .32ACP handgun similar in style to the Browning model 1910. About 5000 of them were manufactured during WWII, although most of these were sent to China. All the known examples in Western collections are form a fairly narrow serial number range (~2200-3000), which probably represent a single batch rerouted to the Pacific islands, where they were occasionally captured by US troops.

In 1943, Hamada was asked to develop a pistol in 8mm Nambu to simplify ammunition logistics, and this would become the Type 2 Hamada.