Restart of the ferry flights began a week after a fatal crash of a U.S. military helicopter, Kyodo News reported.
Eight tilt-rotor Ospreys were offloaded from a ship at the U.S. Marine Corps Air Station in Iwakuni, then flown to the base at Futenma, Okinawa. They are part of a 12-Osprey delivery.
Reacting to the deliveries, Prime Minister Shinzo Abe reiterated a pledge that he would make every effort to relieve the residents of Okinawa of the burden of hosting the majority of U.S. forces in Japan.
"It is our policy to give priority to considering the lives of local residents," he said.
The delivery flights were stopped after an HH-60G Pave Hawk helicopter crashed during an Aug. 5 training flight at another U.S. Marine Corps base in Okinawa, killing one of the four crew members aboard.