Muv-Luv Alternative

In Muv-Luv Alternative , Takeru wakes up three years after the end of Muv-Luv Unlimited to find himself back in his room. Although he first thinks that everything that had happened to him was 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 something like Alternative V , he decides to help professor Kouzuki to complete Alternative IV and save mankind. (Source: Wikipedia)