It is their politician's strategy to get their power.
Of course, Dokdo could be involved to Japan long time ago even if we Korean or Japanese has the evidence to have that island before in each side.
The important FACT is that Dokdo is one island of Korea now and don't have to mention anything about this.
If Japanese say Dokdo is theirs, I wanna say Japan is one of Korean islands because your King is Korean descent and Japan was conquered by Korea long time ago. Thus, just keep quiet please.
Does my words make sense? You Japanese understand?
Another thing is that even Japanese historian have been distorted your own history.
Thus, we cannot believe any of your evidence. So, just believe what our history book said.
Takeshima may or may not be territory of Japan. TBH, I could care less. Only the ones whom this controversy really affects are fishers and the Liancourts have been under control of ROK thru-out postwar. What I find to be annoying is Southkoreans seem to be actively exploiting this to promote their national pride and suchlike. Seriously, choose better things if you want to be proud of your country.