The above is a notice board made in 1839 in Japan. It says something to the effect:
We investigated the case of Yauemon and executed him and other eight men because they sailed to Takeshima, where it is forbidden to sail. Not only is is forbidden to sail abroad but also it is forbidden to meet foreign ship. In 1693, we banned making fishery by sailing to Takeshima.Chosun libo /Japanese version
Korea presupposes for some reason that
(1) Dokdo and Ulleungdo was treated as one body.
Based on the Japanese note board above, Korea claims that
(2) To ban sailing to Ulleungdo means to ban sailing to Dokdo.
(3) Therefore, Japan banned sailing to Dokdo because she recognized it as Korean territory.
Japan's counterargument is as follows.
First, at the time, Ulleungdo was called Takeshima, and Dokdo was called Matsushima in Japanese. See the maps below.
It may be true that Japan abondoned Ulleungdo before, but the point is whether Japan abondoned Dokdo also.
There is a record of judicial review about the the case in question. The judgment reads:
Yauemon was executed because he sailed to Takeshima(Ulleungdo) in the name of sailing to Masushima(Dokdo).(無宿狩込一件 『島根県史』第三章沿革 page ３０６)toron
It is most reasonable to understand that at the time sailing to Ulleungdo was prohibited but sailing to Dokdo was permitted. If that is the case, it just goes to show that at the time Dokdo/Takehima was recognized as Japanese territory by Japan where it is permited to sail around.
Anyway how can Koreans can consider Ulleungdo and Dokdo one body when they had never recoginized Dokdo?