Urusei Yatsura: Only You

When everyone in town receives invitations to Atarus wedding, they are shocked to see that his sweetheart Lum is not the bride. Eventually they learn that when Ataru was playing games as a little boy, he stepped on a girls shadow. Unbeknownst to him, the girl was from extraterrestrial culture where stepping on ones shadow is a form of marriage proposal, and now she and her family have come back to see that Ataru keeps his promise. If he manages to get out of this without being killed by her folks, hell still have to avoid being torn apart by the hands of Lum.