The Ki-84 holds the record for the most produced aircraft in Japan in a single year, ever. That was 1944, not 1945.
About 500 Ki-84-I-Otsu were built (four Ho-5 20mm cannon) and about 3000 Ki-84-I-Ko (two Ho-103 12.7mm machine gunsand two Ho-5 20mm cannons). A very few, less than 5, were built with two 20mm and two 30mm, but they never saw combat so far as I have ever found.