Japanese Prime Minister Fumio Kishida, who is set to retire at the end of this month, returned to Japan Saturday after wrapping up a two-day trip to South Korea for a summit with President Yoon Suk Yeol.

The summit was significant in that the leaders affirmed the possibility of sustaining "shuttle diplomacy" between Korea and Japan. The bilateral ties of the two countries were tense under former President Moon Jae-in, then Yoon restored them considerably by resolving a historical issue and visiting Japan in March last year for a summit with Kishida, who paid a reciprocal visit to Korea later. Their diplomatic efforts to normalize relations between the countries led to stronger security and economic cooperation involving the United States.

In the summit at the presidential office in Seoul on Friday, Yoon and Kishida signed an agreement to cooperate in evacuating citizens of their countries from conflict zones in third countries during emergency situations. They also agreed to cooperate to mutually introduce a system for advance immigration screening of Korean and Japanese visitors before their flight departures from Japan and Korea.

Just a day before Kishida's visit to Seoul for the summit, Tokyo handed over a partial list of Koreans who perished aboard a Japanese ship, the Ukishima Maru. A mysterious explosion sank the ship on its way to Korea shortly after Japan's colonial rule ended in 1945. Thousands of Koreans who were forced into labor in Japan were being repatriated aboard the ship. The Japanese government had ignored or had no intention to look into the case. It was the first time in 79 years that Japan had provided any sort of list related to the incident, though this one is still incomplete.

The accords on concrete cooperation plans will give momentum to Korea-Japan relations. Particularly, the list of passengers on the ship is meaningful in that it opened the way, albeit belatedly, for bereaved families to confirm their loved one's deaths and get closer to the heart of the incident. Japan should make similar efforts on other historical issues.

Some Korean politicians inciting anti-Japanese sentiment just for political gain should be criticized, but controversies destabilizing Korea-Japan ties cannot but recur as long as Japan fails to show a sincere and frank attitude toward issues related to its colonial domination of Korea. At the summit with Yoon, Kishida reaffirmed his existing position on the issue of history without any apology.

The Yoon government decided to compensate Koreans forced into labor for Japanese companies during Japan's colonial rule through a "third party," such as a government fund, despite domestic backlash on the decision and the Supreme Court ruling that the Japanese companies should compensate the Korean victims directly. Tokyo strongly opposed the ruling, which was issued in the days of former President Moon.

Yoon made the bold decision in a bid to normalize Korea-Japan ties, which underpin the Korea-US alliance. There's no doubt that cooperation between Korea and Japan in security and economy serves their mutual national interests amid heightened geopolitical tensions.

Cooperation with Japan is important for the security of South Korea in an emergency involving North Korean threats because rear bases of the United Nations Command that can support US forces in South Korea are in Japan. It is also important in view of Korea's external economic relations. In a situation where China can disrupt global supply of key materials, the necessity of cooperation with Japan is growing.

Seoul and Tokyo must further their relations restored through a tough path by Yoon's daring solution to a historical issue. The next leader of Japan should take up where Kishida leaves off to help relations deeply take root.

Next year will mark the 60th anniversary of the normalization of diplomatic relations between Korea and Japan. The Korea government must make greater efforts to add momentum to its friendly ties with Japan. The government in Tokyo needs to be more sincere on historical issues to keep up good relations with Korea.