Why some Japanese carrier aircraft had folding wings

Did Japan never develop folding wings for its carrier aircraft?

Japan used simple folding wings on aircraft such as the Kate. The criticism applies more narrowly to fighter design, where folding arrangements conflicted with other performance and material choices.

Japanese carrier aircraft did use folding wings: the Nakajima B5N Kate and other types had simple folding arrangements. The original claim was later narrowed to fighters. Japanese fighter wing shape and structure followed the desired performance, available aluminium and other resources, and the way the aircraft were intended to fight. Folding wings were desirable, but they did not fit the other choices made for these fighters. The accompanying criticism of aircrew policy concerns experienced aviators being lost through repeated operations without a system that steadily transferred their experience into an expanding training cadre.