Official prewar documents confirming Japan’s granting of phosphate prospecting rights around Takeshima have been discovered.
These records provide strong evidence of Japan’s effective control prior to South Korea’s illegal occupation and could serve as key material in proceedings before the International Court of Justice.

2016-03-27
The following article appeared on the front page of the morning edition of the Sankei Shimbun on March 25.
With regard to Takeshima (Oki-no-Shima Town, Shimane Prefecture), which South Korea continues to occupy illegally, official documents have been discovered through an investigation by the prefectural Takeshima Archives showing that the Japanese government had established phosphate prospecting rights in the surrounding area before the war.
While phosphate mining on Takeshima had previously been known through interviews and other sources, this marks the first time documentary evidence confirming it has been identified.
The discovered materials consist of a “Prospecting Register” authorizing phosphate prospecting around Takeshima and a “Mining Area Map” submitted by the applicant at the time of application.
They are held by the Chugoku Bureau of Economy, Trade and Industry and are believed to have been transferred from its predecessor, the Osaka Mining Supervisory Office of the former Ministry of Commerce and Industry.
According to the Prospecting Register, in June 1939 the government established and registered phosphate prospecting rights for two applicants residing in Tottori Prefecture over 83,800 tsubo (approximately 270,000 square meters) covering the island and surrounding waters of Takeshima, and after the war the rights were transferred to another individual before being deleted from the register upon expiration of the term in February 1949.
The Mining Area Map shows that at the application stage in June 1934, prospecting over 200,000 tsubo (approximately 660,000 square meters) was requested, but in August 1938 the application was revised to 83,800 tsubo (approximately 270,000 square meters), for which prospecting rights were ultimately granted.
Previous investigations have revealed that sea lion hunters active around Takeshima at the time opposed phosphate mining, arguing that it would interfere with their hunting activities.
The newly discovered documents indicate that the government took such concerns into account by excluding coastal areas and other sea lion habitats when granting the prospecting rights.
Masao Shimojo, Professor of Japanese History at the Faculty of International Studies, Takushoku University, who is well versed in the Takeshima issue, commented as follows.
“Prior to South Korea’s illegal occupation of Takeshima in 1952, no evidence has ever been found that South Korea exercised state sovereignty over the island.
These documents will serve as powerful evidence demonstrating Japan’s effective control over Takeshima at the time, should the issue be referred to the International Court of Justice.”