Manga by author Age

Based on the game by Age, sequel to MuvLuv Unlimited, taking place in an alternate universe where the Earth is invaded by aliens. From Wikipedia: In Alternative, Takeru wakes up three years after the end of 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 Kouduki to complete Alternative IV and save mankind.

Based on the game by Age, spin-off of the Kimi ga Nozomu Eien game.From Solaris-SVU:Takeru and Sumika have been neighbors and friends since they were little, but when a mysterious girl arrives, and is found in bed with Takeru, their daily lives will be thrown into chaos.