When aliens known as the Oni threaten to invade the Earth, they promise to leave under one condition—a randomly-chosen human must win a one-on-one game of tag against Lum, the beautiful daughter of the Oni leader. The "lucky" person selected happens to be the lustful and unlucky high schooler Ataru Moroboshi. Given 10 days to attempt to grab Lum's horns, Ataru realizes how impossible the challenge is as he is faced w...