 The name "Urusei Yatsura" is a pun within a pun. In normal Japanese,  the name would be spelled "urusai yatsura" (meaning "obnoxious  people"). However, the title is spelled with the Japanese kanji  karacter for "star" ("Hoshi" or "sei") making it "Urusei Yatsura"  which could be interpreted as "jerks from Planet Uru," "Those  annoying bastards from the planet Uru" or as Animeigo had it for a  while, "Those Obnoxious Aliens."