Japanese ports and harbours are classified into 4 types stipulated in Article 2(2) of Port and Harbor Act under follow;
A port serving as the hub of an international ocean freight transportation network for long-distance international ocean freight shipping, having advanced functions to connect the international ocean freight transportation network and the domestic ocean freight transportation network, which is specified by Cabinet Order as a port and harbour that requires intensive efforts to strengthen its international competitiveness.
A port other than strategic international hub ports, which is specified by Cabinet Order as a portserving as the hub of the international ocean freight transportation network.
A port other than strategic international ports or international hub ports which is specified by Cabinet Order as a port serving as the hub of a maritime transportation network or as a port having a great bearing on the national interests.
A port other than strategic international hub ports, international hub ports, or major ports.
At present, the majority of port management bodies are comprised of prefectural governments or municipal governments.
Port and Harbour Handbook of Japan 2020 (p1)