This Boy Can Fight Aliens!

When unstoppable aliens invade, it seems that all is lost until a teenager with the ability to defeat these invaders appears. With no memories of who he is or how to use his power, Kakashi will need the help of Commander Shiro and Staffer Arikawa if he wants to take down this threat. But when Kakashi moves in with his newly appointed guardians, the triangle of confusing emotions that arises will make him question his own motivations and put the fate of the entire world in jeopardy.