"Muv-Luv Unlimited" explains that the BETA first arrived on Earth in 1973 (in China and Canada) after arriving on the Moon in 1967 and being spotted on Mars in 1958. Subsequent battles with BETA resulted in the global population dropping to 2.4 billion with most of mainland Eurasia having been lost by the time the game starts in 2001. Most of the major characters from the "Extra" timeline are present in "Unlimited", notably excluding the "Unlimited" world's Takeru, who is said to be dead, and Sumika, who does not seem to exist in the "Unlimited" timeline. The characters are mostly identical to their "Extra" counterparts, with the notable exception Yoroi, Takeru's best friend in Extra who, for reasons unclear, is a girl in this reality.