Beautiful space alien princess Lum invades Earth on her UFO, and unlucky Ataru Moroboshi's world gets turned upside down! Will Lum become Earth's electrifying new leader? Or will Ataru somehow miraculously save Earth from space alien onslaught?

In a high-stakes game of tag, Ataru must touch Lum's horns in ten days--or aliens will take over the earth! The fact that Lum can fly doesn't make Ataru's job any easier. As it turns out, the game of tag is only the beginning of Ataru's troubles, as he continues to attract strange encounters with otherworldly beings like beautiful snow spirit Oyuki and the sexy crow goblin Princess Kurama!