Konpeki no Kantai

Konpeki no Kantai (紺碧の艦隊) or 'Deep Blue Fleet' is a Japanese alternate history novel that was adapted into an OVA series by J.C. Staff. The series explores a alternate timeline where Japan manages to defeat the United States in the Pacific War before joining the United Kingdom in its war against Germany. A spinoff set largely in Europe called Kyokujitsu no Kantai (旭日の隊) or Fleet of the Rising Sun was written and then also adapted into an OVA by J.C. Staff.