Maritime exercises were held in Tokyo Bay after a five-year pause.
Japan flexed its military muscle on Saturday, as regional tensions multiply.
The Japanese coastguard resumed annual drills in Tokyo Bay, after a five year pause.
A mock rescue scenario was staged just days after a very real flare-up with regional rival China.
On Thursday, Japan scrambled fighter jets after Chinese coastguard vessels entered what Tokyo considers its territorial waters near disputed East China Sea islands and a drone-like object flew near one ship, Japan said.
As Saturday’s exercises unfolded, Japan’s Minister of Land, Infrastructure and Transport, Keiichi Ishii, said: “The role of the Japanese Coastguard is becoming all the more important with the surveillance of waters around the Senkaku islands, and dealing with repeated missile launches by North Korea.