[3] On the other hand, as the deterioration of offshore security became more serious due to the demobilization of the Japanese Navy, in 1946, the Japan Coast Guard became a law enforcement agency under the Ministry of Transport, incorporating these former Navy-derived sweeping units.

However, at the time of its establishment, in response to instructions from the GHQ Civil Affairs Bureau in consideration of the backlash from the Far Eastern Commission against the armed Japan Coast Guard ships, strict restrictions were imposed on displacement, armament, and speed in order to clearly indicate that the patrol boat was not for military use.

[4] In October 1950, after receiving an informal consultation regarding the Tacoma-class frigate (PF) loan from the US Far East fleet, former Admiral Kichisaburo Nomura, former Admiral Zenshiro Hoshina, and former Demobilization Agency Second Rehabilitation Bureau, an informal study of the Navy's revival was undertaken, centered on Navy personnel.

On 19 October 1951, at a meeting between Prime Minister Shigeru Yoshida and General Matthew Ridgway, Supreme Commander for the Allied Powers (SCAP), 18 frigates (PF) and 50 landing support crafts (LSSL) were proposed.

Then, in order to accept these vessels and establish an operation system, the Y Committee was set up as a secret organization under the direct control of the Cabinet and examined it.

The members of the Y Committee were appointed by former Navy personnel and the Japan Coast Guard Officer, and were in close cooperation with the US side.

Also, on the same day, the Japan Coast Guard's route enlightenment work was transferred to the Coastal Security Force along with the minesweeper and its personnel.

In addition, the capacity at that time was 7,828 (7,590 guards, 238 workers), excluding those whom were hired for a period of up to two months and those who were on leave and those who were part-time.

On 14 January, the first vessels (6 PF, 4 LSSL) based on the Japan-US Ship Lease Agreement was delivered, and the 1st, 2nd, and 11th fleets were reorganized on the same date.

[6] From 28 June to 10 July, was the first disaster dispatch of the Coastal Security Force for flood damage in western Japan (Shimonoseki, Kure, Osaka, Sasebo route enlightenment corps).

In this 12-day activity of 41 minesweepers in total, the results of communication support, clearing of route obstacles, about 338 tons of relief supplies, and marine transportation of 20 people were achieved.

Originally, the predecessor Coastal Safety Force was an organization that was established to centrally operate the Tacoma-class frigate (PF) provided by the United States, but it took time for diplomatic and political procedures and ship maintenance.

The official delivery was not in time for the Coastal Safety Force era, and the ship was only undertaken for storage (borrowing) after the maintenance was completed.