Flying drones above and around airports are prohibited.

Flying drones and radio controls above and around airports is prohibited. In order to ensure aviation safety, certain airspace must be kept free of obstructions with respect to the area around the airport. There are height restrictions around Kansai International Airport based on the Civil Aeronautics Law. Violation of this rule may be subject to the penalty set forth in the Civil Aeronautics Act and compensation for any damage or loss incurred.

When you see a drone and radio controls around the airport, please inform the police (telephone 110) immediately.

For details, please refer to the link below.
Japan’s safety rules on Unmanned Aircraft/Drone(MLIT website)