After an alien invasion threatens to annihilate the human race, a young Japanese girl, named Milly, travels back in time from 2084 to October 2002, and enlists the reluctant aid of skilled Tokyo gunman, named Miyamoto, to discover and prevent the start of the war. However, trouble ensues when the two protagonists are forced to deal wit...
Alien pods come to Earth and, naturally, start taking over Human Hosts. One such pod only manages to take over one human's, Shin Izumi, right arm. Together they grow and co-exist, all the while the other aliens are making meals of other humans; Shin feels he must put a stop to it all, but his alien, Migi, doesn't see why.