The awaited visual novel, Muv-Luv, will be portable soon. PQube and ixtl are working to make Muv-Luv, which consists of Muv-Luv Extra, Muv-Luv Unlimited and Muv-Luv Alternative to be available on PlayStation Vita. The games will be provided both physically and digitally in North America and Europe this upcoming summer.
Previously, Muv-Luv Extra and Muv-Luv Unlimited have been released for PC on February 28, 2003. While Muv-Luv Alternative as the sequel was released April 24, 2006 which the story follows Muv-Luv Unlimited.
Taken from Wikipedia, you can see the story of Muv-Luv Unlimited here:
In Muv-Luv Alternative, Takeru wakes up three years after the beginning of Unlimited to find himself back in his room. Although he first thinks that the events of Muv-Luv Unlimited were a dream, he soon feels that something is wrong, and leaves the house to find that he has been sent back in time to the beginning of the events in Unlimited. Unwilling to accept the events at the end of Unlimited, he decides to help professor Kouzuki save the earth and mankind by bringing Alternative IV, a secretly planned assault on the first BETA hive, to fruition.
The games’ trailers also have been published for Muv-Luv and Muv-Luv Alternative to show you how the game will look like in PlayStation Vita. Check it out!