All hope seems lost when the world is suddenly invaded by aliens. Earth's only defense is a small three-person team known as the Special Counter-Aliens Task Force, consisting of an anonymous director, the tyrannical Shiro, and the easygoing Arikawa. The luck of the Task Force improves when Arikawa finds a teenage boy lying alone on a hill. The boy, Kakashi, is humanity's only hope—he has power previously unbeknownst capable of defeating the aliens! However, without any memories and with no knowledge on how to use his power, Kakashi is left clinging to Arikawa and Shiro as well as the only remnant of his previous life: his broken cellphone. Kakashi is conflicted by the fears and emotions clouding his mind and he calls his own motivations into question. Can he overcome his doubts and internal struggles and save the world? When aliens suddenly invade the world, Earth seems to be fighting a losing battle until Arikawa, one of the defense command staff, accidentally discovers a young man lying on a hill. Tests soon prove the impossible: this one teenager, Kakashi, has the power to defeat the attackers! Unfortunately, Kakashi has also lost his memory, and with it the knowledge of how to actually use his power. Moving Kakashi in with himself and his own commander, Shiro, Arikawa accidentally starts a strange triangle of emotions and relationships. A triangle that threatens the fate of the planet as Kakashi begins to question his own motivations!