An unlucky and lecherous high school student, Ataru Moroboshi, is chosen to play tag against the alien Lum Invader to decide the fate of Earth. When he wins the game, securing his ability to marry his girlfriend Shinobu Miyake, the alien Lum misinterprets his victory cry as a marriage proposal to her. She falls in love with him, declares him her "Darling," and moves in, becoming his constant companion and shocking him whenever he flirts with other girls, setting the stage for a series of hilarious and often chaotic mishaps.
