One night the world is invaded by strange parasite aliens who snuck into peoples' rooms and destroyed their brains by entering their ear as they slept. Well everyone except for Shinichi who managed to escape thanks to his ear buds and his fear of bugs. He managed to stop the creature in his arm. However, it was not a complete victory as not the creature inhabits his right arm.

Now that Shinichi knows the truth about the horrible killings that are being committed by these other aliens, he drags along his alien to help him stop all the other aliens. You know when the the alien is not asking him to show off the amazing powers of his human body.