Urusei Yatsura Movie 5: Kanketsu-hen

Lum is suddenly taken away by Lupa, a man tied to an old promise between their families. His arrival also brings a dangerous threat to Earth, forcing Ataru and Lum toward one final game of tag whose outcome will decide far more than their relationship.

Ataru can end the crisis simply by telling Lum that he loves her, yet his stubborn pride makes those words almost impossible to say. As the deadline closes in and the fate of Earth hangs on their chase, Lum must decide whether Ataru's actions can express the feelings he refuses to put into words.