Persuade South Korea (the ROK) to accept Japan's proposal on territorial dispute over islets. The ROK is illegally occupying Japanese Territory Takeshima. The ROK calls it Dokdo.
Although Japan proposed to the ROK that the dispute be referred to the International Court of Justice, the ROK rejected this proposal.
In the drafting process of The San Francisco Peace Treaty, United States Assistant Secretary of State for Far Eastern Affairs Dean Rusk rejected the request by the ROK that Takeshima be added to the relevant article of the Treaty as one of the areas Japan would renounce.
This is not just bilateral issue between Japan and the ROK but deeply involves the United States and your inescapable responsibilities in Northeast Asia.
Going to the ICJ is a peaceful and fair manner to settle the dispute.