Mitsubishi decided to modernize the Type 97-Kai Shinhoto Chi-Ha in 1942. The armor was increased to 50 mm with a straight flat plate to simplify production. The armor was welded.
The engine in the Type 1 Chi-He was a Type 100 (240 HP).
Production was delayed by having to retool the factories and the emphasis of production going to aircraft. Plenty of turrets were produced and were supplied for the Shinhoto Chi-Ha.
Only units in Japan received the Type 1 and it never saw combat.