For nearly 33 years, people drove on the right-hand side of the road in Okinawa because the prefecture was under the jurisdiction of the U.S. Although Okinawa was reverted to Japan on May 15, 1972, it took almost six more years to change the traffic rule back. The change in 1978 was commonly called “Nana San Maru (Seven, Three, Zero)” because it took effect on July 30 of that year.