◇ ‘What is “Muv-Luv UNLIMITED: The Day After”’
A spin-off title of the Muv-Luv series, which follows on from ‘Muv-Luv’ and ‘Muv-Luv Alternative’.
The first entry in a spin-off series branching from “Muv-Luv Unlimited”, a story that diverges into a different future from the anime-adapted “Muv-Luv Alternative.”
After the protagonist Shirogane Takeru sees off the heroine’s escape from Earth in “Muv-Luv Unlimited”, this story portrays the people left behind on Earth who, even so, continue to fight against their fate of destruction.

◇ Story
The human evacuation plan to the Barnard’s Star system was executed, and five days after the large-scale gravitational anomaly triggered by humanity’s desperate counteroffensive, Operation Babylon, the people left behind on Earth continued their struggle for survival.
A small group of survivors gathered aboard the stranded U.S. aircraft carrier JFK, desperately seeking a place of safety.
That day, U.S. Marine Second Lieutenant Wilbert D. Collins, while on a reconnaissance mission, picked up a faint distress signal and set out to investigate.

More details on the official game page of Muv-Luv Unlimited: THE DAY AFTER - Episode 00 REMASTERED ...