Ground Self-Defense Force personnel boarded MV-22 Osprey aircraft for training for the first time Wednesday.
During a joint drill open to the media, about 50 members of the GSDF Western Army Infantry Regiment for defending Japan's remote islands boarded four of the tilt-rotor aircraft to practice recapturing an islet occupied by an enemy.
The drill involving the Self-Defense Forces and the U.S. military was designed to demonstrate their close cooperation amid the territorial dispute over the uninhabited Senkaku Islands, which are under Japan's control, in the East China Sea.
The drill was also aimed at emphasizing the safety and usefulness of the Osprey, which has a record of fatal crashes.
The U.S. stationed 12 of the transport aircraft in Okinawa last October, triggering local protests.
The Defense Ministry has earmarked ¥8 million in the draft fiscal 2013 budget to study Osprey operations with an eye to buying them for the SDF in the future.