There are 2 Primary Muv-Luv Universes with branching paths within.
The universe where Muv Luv Extra takes place.
History is assumed to be similar to real life but with some alterations.
From the Alternative branch in the BETA universe, this version of the Extra universe emerges after a Causality Conductor forcefully exits from the Alternative branch. Due to this unnatural event, a connection is formed between the Alternative and Extra branch causing information to leak to or from each universe. The Alternative universe began leaking information over to this Extra-like universe, while the Extra-branch responded by leaking information out into the Alternative universe.
Land of CatsEdit
A briefly mentioned universe where everyone is supposedly a cat. A brief connection existed between Extra and the Land of Cats when Tsukiji traded places with her cat self.
The universe where Muv Luv Unlimited, Total Eclipse and Schwarzenmarken takes place and also where the BETA exists.
History is based on Extra, but because technology is much more advanced and because of the existence of the BETA, there are a lot of divergences. These include the peaceful restoration of Imperial rule in Japan in 1867 (with the resultant continuation of the Shogunate) and the end of World War II, wherein the atomic bombs were dropped on Germany, not on Japan. A boom in space exploration saw the establishment of several space stations, lunar bases, and the eventual discovery of the BETA.
Diverges from the Alternative Universe on October 22, 2001. Eventually leads to the use of Alternative V and the scenario seen in The Day After.
See Unlimited/The Day After Timeline for more.
A single branch which diverges from the Unlimited Universe on October 22, 2001 and is the branch where Muv Luv Alternative takes place. Eventually leads to the success of Alternative IV, the destruction of the Original Hive and the formation of the Final Extra Universe by the 00 Unit.
See Alternative Timeline for more.
Final Extra/Altered FableEdit
A universe created by the 00 Unit for Shirogane Takeru to rest to after the end of his unsung journey in the Alternative branch.
Highly similar to the Extra universe, but includes a lot of alternations influenced by the Alternative branch.This includes Yoroi Mikoto no longer hiding her gender as a girl, Mitsurugi Yuuhi surviving her death in Extra and falling in love with Shirogane, the existence of Yashiro Kasumi, and overall more intimate feelings towards to Shirogane Takeru by his friends.
Possibly a branch from the Final Extra Universe, or a separate universe. The company creator, age, mentions with a message that plays upon start up of Altered Fable that the game was not related to Final Extra, this is eventually retconned with Photon Melodies and is name as a sequel to Shirogane Takeru's adventures in Alternative.