The distance between Dokdo and Oki island, the nearest island of Japan from Dokdo, is about 157 kilometers, which is approximately 68 kilometers farther than that between Korea's Ulleungdo and Dokdo. Also according to the Sejong chronicles, an official letter during Joseon dynasty, the distance between Ulleungdo and Dokdo is close enough to see Dokdo from the other if the weather is fine. In 1900, Dokdo was officially incorporated into Gangwon-do province through the forty-first article of Korea's imperial order. Even some documents from Japan support that Dokdo belong to South Korea's territory.

Second, historical records also support that 'East Sea' is the appropriate name for the sea. The term 'East Sea' has been used for more than 2000 years, and Samguksagi(三國史記), King Dongmyeong's episode, Eight State Map(八道總圖) as well as a variety of historical maps support this fact. In contrast, it hasn't been 100 years since the term 'Sea of Japan' was first used.