Ms. Pac Man and Crazy Otto (Arcade; 1981).
Do you know the story of these two? In 1981, hackers from the Bedford, Massachusetts-based General Computer Corporation modified the software in an old Pac Man arcade cabinet to make a more interesting game, which they dubbed Crazy Otto. Sensing something great, the Midway Corporation of Chicago purchased the rights to Otto later that year, modifying it into the more marketable Ms. Pac Man, which proceded to become a smash hit in U.S. arcades. Of course, the Pac Man franchise itself was actually owned by the Tokyo-based Namco cooperation, and (I believe still within the course of the same year) Midway agreed to cede control of their unauthorized spin-off back to their Japanese overlords. To this day, Ms. Pac Man remains a relatively obscure, or at least forgettable, presence in the Japanese video game canon, as opposed to the generational icon status she enjoyes in the States.