the Germans invented Fanta in WWIIs when it stopped being possible to import coke. were there any Japanese attempts to come up with home grown replacements for western products they couldn't get during the War?

by grapp
RyukyuKingdom

Such an attempt was certainly done with beer. Check out Brewed in Japan by Jeffrey Alexander. Chapter 3 documents Japan's efforts to keep beer available as a ration for soldiers and civilians alike as well as a source of wartime revenue. Japan could no longer rely on German ingredients or brewers and eventually reorganized the beer industry to meet wartime demands. Efforts were made by Dai Nippon to grow hops in Hokkaido and Nagano by 1940, and Kirin was already growing hops in Korea since 1934 and carefully imported US seedlings to plant in Honshu in 1939. Dai Nippon was more successful and thus helped to supply other firms during the Pacific War. In 1942, Japanese beer firms were asked to unify their manufacturing and distribution system, which removed differentiation and branding from wartime beer. With rice distribution being more tightly controlled than barley, beer actually ended up being brewed and consumed more than saké, especially after saké production was stopped.