It has been 11 years because the Senkaku Islands in Okinawa Prefecture have been nationalized.
In the encircling waters, ships operated by the Chinese Coast Guard are a daily incidence.
NHK analyzed the actions of ships operated by the Japan Coast Guard utilizing knowledge despatched by AIS (Automatic Identification System) put in on ships, and located that in recent times there was a big enhance in exercise in waters north of the Senkaku Islands. I discovered that
(Society Department reporter Tatsuya Yamashita)