We have heard this before (yonhap):
Seoul's latest territorial row with Tokyo over a cluster of rocky islets in the East Sea dates back to Japan's colonial rule of the Korean Peninsula in the early part of the last century, analysts said Tuesday.
Uh, no it does not.
The analysts are referring to the 1905 annexation of Dokdo (Takeshima to the Japanese) by the Shimane Prefecture. Perhaps the Japanese had problems with local authorities taking too much initiative (remember the Manchurian incident?) but a prefecture has no authority to lay claim to territory on its own incentive. The annexation was just a reorganization of territory already claimed by the Japanese, at claim going back to the early 17th century. In fact, the Japanese were making effective use of the islands (fishing outposts and such) decades before the annexation.
Please note that I am NOT supporting Japan's claim, just noting that the guys quoted in Yonhap are playing loose with the facts.