In his March 25 letter, Naoyuki Agawa of the Embassy of Japan claimed that Dokdo belongs to Japan. Historically and legally, Dokdo is part of the Republic of Korea.
Korea has exercised jurisdiction over Dokdo since the sixth century. However, the islands unilaterally were incorporated into Japan in 1905 with the purpose of supporting Japan's military campaign during the Russo-Japanese War. Dokdo was the first parcel of Korea's sovereign territory that Japan seized in the course of its colonization of the Korean peninsula. After having been under Japanese colonial rule for nearly four decades, Dokdo was reinstated as Korea's territory when Korea was liberated from Japan in 1945.
Further, it was only in the wake of the Russo-Japanese War that the term "Sea of Japan" gained increased usage to designate the body of water legitimately known as the "East Sea." For obvious reasons, this historically tenuous appellation had been disseminated by the Japanese during their colonial rule of the Korean peninsula.
Minister for Public Affairs
Embassy of the Republic of Korea