Konpeki no Kantai

is a Japanese alternate history series produced by J.C.Staff. The series focuses on both a technologically-advanced Imperial Japanese Navy and a radically-different World War II that were brought about by Admiral Isoroku Yamamoto's revival by unexplained circumstances. Both the published books and the original video animation (OVA) series are also notable for using the Imperial Japanese calendar, instead of the Western calendar, in denoting the years in which the events of the series take place. It also spawned a 1997 OVA side story, , one manga sequel, and two turn-based strategy games for the PC-FX and the Super Famicom.