The Yomiuri Shimbun reported that Tokyo is interested in procuring the General Atomics Avenger to monitor Chinese warships.
By MC1 Peter D. Lawlor [Public domain], via Wikimedia Commons
The unmanned combat air vehicle will be operated by the Japan Maritime Self-Defense Force if procured. The timeline to enter service is late 2020s.
The aircraft will be flown above manned platforms such as the P-1 but below the RQ-4 which Japan has ordered. They will be used to monitor Chinese warships sailing nearby.