However, in 1946, an "Illegal Immigration Control Headquarters" was established in the Ministry of Transport after cholera was transmitted to Kyushu by smugglers from the Korean Peninsula.

[3][4] Meanwhile, the GHQ/SCAP also recognized the deficiencies of the Japanese maritime security system and in March 1946 Captain Frank M. Meals of the United States Coast Guard (USCG) was tasked to consider the situation.

[5] In 1952 the Coastal Safety Agency was created with ships supplied by the United States and spun off in 1954 as the Japan Maritime Self Defense Force.

Immediately after the end of World War II, a large number of aerial mines laid by the US military were left in the waters around Japan, and clearing them became an important mission of the MSA.

[7] In October 1999, Prime Minister Keizō Obuchi presented a series of major maritime anti-piracy cooperation proposals to ASEAN members.

Nonetheless, these ideas finally materialized somewhat in 2001 when armed Japan Coast Guard ships ventured into foreign waters in order to provide Indian, Thai, and Filipino maritime forces with anti-piracy training.

[8] In May 2000,[9] the Japan Coast Guard introduced a nationwide emergency number, 118, for reporting accidents at sea, oil spills, suspicious vessels, smuggling, and illegal immigration.

[9] On December 22, 2001, Japan Coast Guard ships intercepted a Chinese-flagged vessel, believed to be North Korean in origin, in the Japanese Exclusive Economic Zone between Kyushu and China.

[17] In contrast, the China Coast Guard is allowed to use force against foreign governments or naval vessels, which are supposed to be protected by international law.

The JCG maintains three national-level elite units for each specialized fields: Immediately after its creation, the MSA operated the second-hand ships of the former Japanese Navy, but it was only allowed to use smaller and slower vessels.

However, these copies of American ship types were found wanting as they neither suited the actual operational work of the MSA nor the sea conditions around Japan.

[25] In the late 1970s, it was clear that the new international rules on national exclusive economic zones would demand a considerable increase in the size of the Maritime Safety Agency fleets.

In addition, the Japan MSA also began protecting shipping operations by deploying air-sea rescue helicopters on-board PLHs.

[26] Since the 1980s, criminal ships had advanced into Japan's ocean spaces and were showing high speeds, also North Korean armed trawlers (fushin-sen) began to appear.

Another half dozen ships including three Tsugaru-class are stationed 412 km (256 mi) north of Ishigaki at JCG's 11th Regional Coast Guard Headquarters at Naha.

Because the Allied countries wanted to maintain the disarmament of Japan, the weapons allowed to be carried by the MSA were restricted to only small arms in the earliest days.

However, following the outbreak of the Korean War, the need to strengthen the security capability of Japan became necessary, and starting in 1954, the installation of larger guns on MSA ships began.