As the 50th anniversary of the signing of the treaty that normalized ties between Japan and South Korea — June 22 — draws near, both countries should seize all opportunities to improve bilateral ties, which have been in a chilly state for some time. There are signs of momentum building toward better ties. It must not be impeded.

On Tuesday, senior foreign and defense officials from the two countries held dialogue on security issues in Seoul for the first time since December 2009. A day earlier, Japan held ministerial-level meeting on water-related policies with South Korea and China in Gyeongju, a historic city in the southeastern part of South Korea. On Thursday, high-ranking foreign and defense officials from Japan, South Korea and the United States held separate meetings in Washington.

Following a tripartite meeting in Seoul in late March involving Foreign Minister Fumio Kishida and his counterparts from China and South Korea, Cabinet ministers in charge of tourism from the three countries met in Tokyo on Sunday, the first such meeting in four years. The South Korean minister, Kim Jong-deok, who attended the meeting, said, "Tourism exchanges are an important means to deepen friendship and contribute positively to political reconciliation."

Still, significant improvement in bilateral ties will require solutions to problems linked to the two countries' perception of modern history, such as the issue of Korean "comfort women" who were taken to frontline brothels to provide sex for the Imperial Japanese armed forces, the territorial row over the South Korea-controlled Takeshima islets in the Sea of Japan, Prime Minister Shinzo Abe's visit to Yasukuni Shrine, which honors Japan's Class-A war criminals along with the nation's war dead, as well as Japanese history textbooks' description of the comfort women and Takeshima issues.

Abe has reportedly decided not to visit Yasukuni during its regular spring festival in late April, apparently judging that such a visit — strongly opposed by China and South Korea — would have negative repercussions on his upcoming trip to the U.S. Washington is wary of Japan's soured relations with its Asian neighbors and expressed its "disappointment" when Abe last paid tribute to the shrine in December 2013.

South Korea protested against descriptions of the Takeshima issue in social studies textbooks for use in junior high schools that have just passed screening by the education ministry — which highlighted the government's position on the dispute. Seoul has also urged that Abe mention the comfort women issue when he delivers a speech before the U.S. Congress during his visit to Washington.

The latest edition of Japan's diplomatic bluebook referred to South Korea as the country's "most important neighbor," but the description of South Korea as a "country that shares [with Japan] basic values such as freedom, democracy and basic human rights and interests in such matters as ensuring peace and stability in the region" — which was in the 2014 edition — was dropped. Tokyo apparently regarded the travel ban Seoul imposed on Sankei Shimbun's former Seoul bureau chief, who has been indicted on a charge of defaming President Park Geun-hye in his column in the online edition of the newspaper, as a sign of receding freedom of the press in the country. The travel ban was lifted on Tuesday.

South Korea is paying special attention to what Abe will say in his statement this summer to mark the 70th anniversary of the end of World War II. It has strongly called on Japan to make sure that the Abe statement will retain the core part of a statement made 20 years ago by then Prime Minister Tomiichi Murayama on the 50th anniversary of the war's end, in which Murayama expressed Japan's "heartfelt apology" for its past colonial rule and wartime aggression that caused "tremendous damage and suffering" to the people of Asian nations.

These issues remain a thorn in Japan-South Korea ties and it will not be easy to remove it. The rise in nationalist sentiments in both sides not only make solutions difficult but might widen the gap between the two countries. Leaders and officials of the two governments should handle ties with extreme care by seriously considering what courses of action will contribute to building mutual trust and stronger relations.

Ordinary citizens, for their part, should not think that improving Japan-South Korea ties is a job reserved for diplomats and politicians. In Japan, media articles and activities such as hate speech that foment prejudice and antipathy toward South Korea are rampant. They not only have a negative impact on bilateral ties, but also cast Japan in a poor light internationally. Those who engage in such activities should reflect on the consequences of their actions and show some restraint. And the government should crack down on speech that advocates violence against others based on their nationality.