After disbandment following defeat in the Second World War, the Japanese Army was eventually reconstituted in 1954 as the Japan Ground Self Defence Force (JGSDF), strictly limited by the Japanese Constitution to home defence. Its first tanks were U.S.-supplied M24 Chaffee Light and M4A3E8 Sherman Medium Tanks. The Chaffees were replaced in 1960 by M41 Walker Bulldog Light Tanks but replacing the obsolete Shermans proved more problematical. The available options of American M47 or M48 Medium Tanks were considered too heavy for the many lightly built bridges in Japan as well as being too wide for several tunnels in the railway system, therefore the decision was taken to design and build Japan’s first indigenous tank since the Second World War. The result was the Type 61 Medium Tank that entered service in 1962.
It was reputedly based on the M47 that it somewhat resembled and was armed with the same 90mm gun, but at only 35 tons was 12 tons lighter, achieved by reducing the overall dimensions as well as armour protection.