Flying drones above and around airports are prohibited.

Flying drones above and around airports are prohibited.
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 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)http://www.mlit.go.jp/common/001290156.pdf