Grab her horns and she might just become your darling!

An alien race known as the Oni arrive on Earth to invade the planet. Instead of taking over the planet by force, the Oni give humans a chance to fight for the rights to the planet by taking part in a competition. The computer-selected human player is Ataru Moroboshi, a lecherous, unlucky and stupid high school student from the Japanese city of Tomobiki, and the Oni player is Princess Lum, daughter of the leader of the Invasion force.