In 1952, mainland Japan allowed the United States to occupy the island of Okinawa as part of a treaty for the country's independence, known as the San Francisco Treaty, Stars and Stripes reported.
Okinawa and two smaller island areas remained in the control of the United States until 1972, when control of the islands was transferred to Tokyo.
However, the United States continues to have a large presence in Okinawa, as it hosts U.S. air bases and Marine jungle-warfare training grounds.
Prime Minister Shinzo Abe angered Okinawans by deciding to mark the anniversary, which island residents call the "day of humiliation."
"It was like reopening old wounds," said Okinawa resident Mitsuko Kadekaru, 57.
"Prime Minister Abe woke a sleeping dog," said Takeshi Onaga, mayor of Naha, Okinawa's capital.
Meanwhile, Okinawa Gov. Hirokazu Nakaima said much of the tension between Okinawa and mainland Japan stems from the time the treaty was signed, when Japan gave control of the island to the United States.
"At that point, Okinawa was severed from the rest of Japan and cast under U.S. military administration," he said. "The problems on Okinawa today are all stemming from there."