Japanese Prime Minister Takaichi Sanae and South Korean President Lee Jae-myung might be considered an odd couple.
Ms. Takaichi, a staunch conservative in the mold of her late mentor, Abe Shinzo, is known for supporting Japan’s defense buildup and revisionist views of the country’s aggression in World War II. Mr. Lee is a liberal who emerged during South Korea’s 1980s pro-democracy movement, and, like many progressive politicians, has used anti-Japan rhetoric in campaigns.
But despite stark differences, the two leaders are moving past deep-seated historical frictions to forge what by all accounts appears to be a genuine friendship, and are working to bring their fellow citizens with them.
Why We Wrote This
Despite coming from different ends of the political spectrum – and lingering tensions between their countries – Japanese Prime Minister Takaichi Sanae and South Korean President Lee Jae-myung are forging a deep partnership. Recent visits have been a show of pragmatic cooperation and, it seems, genuine warmth.
This week, Mr. Lee and Ms. Takaichi wrapped up their sixth meeting in less than a year – a rare feat – fueling hope that Japan and South Korea are entering a new era of cooperation. This comes as Seoul, Tokyo, and other key U.S. allies in the Pacific are adjusting to pressure from China and a distracted Washington.
“We just started turning, hopefully, the corner” on Japan-South Korea relations, says Kunihiko Miyake, director and special adviser at the Canon Institute for Global Studies in Tokyo. But, he added, “it’s a long, winding road.”
Pragmatism over ideology
Destabilizing geopolitical challenges, including the Iran war, have added urgency to Japan-South Korea cooperation, and domestic political shifts have helped pave the way. But the leaders’ evident chemistry doesn’t hurt, either.
Their meetings have included lighthearted moments, such as an impromptu drum jam session in Ms. Takaichi’s hometown of Nara, Japan, in January. (She was the drummer in a college band.) This week, they listened to musical acts in Mr. Lee’s hometown of Andong, a center of South Korean dance and storytelling. Ms. Takaichi invited Mr. Lee back to Japan for more talks, perhaps with a stop at hot springs.
“The fact that we’ve visited both of our hometowns within just four months is not only a first in the history of South Korea-Japan relations, but also a rare occurrence, even on the global stage,” he told Ms. Takaichi.
“I am truly aware of just how important we are to each other,” Mr. Lee said.
For all their ideological differences, Ms. Takaichi and Mr. Lee have strong qualities in common. Both come from humble backgrounds rather than from the political elite. Mr. Lee grew up in a working-class family and labored in factories as a youth, and Ms. Takaichi is from a middle-class family in Nara.
Both are veteran politicians who have made careers out of being straight talkers, even iconoclastic. And they are pragmatic, willing to put practical goals for their countries first.
“They see in each other people who have come through long political careers, and proven that they can subordinate beliefs to political necessity,” says Dan Sneider, a lecturer in East Asian Studies at Stanford University and a Korea expert. “They have bonded over that.”
They also both have the luxury of being immensely popular with their respective publics. “You’ve got two political leaders with favorability ratings above 60%, so they have some freedom to act even when it’s not totally in line with public opinion,” says Mr. Sneider.
Public opinion shifts
Despite lingering historical animosity, recent opinion polls show the South Korean public is warming toward Japan. A poll released this month found that in 2025 more than 63% of South Korean respondents had a “positive impression” of Japan. This shift comes as the country’s young people in South Korea are becoming more conservative and realistic, says Mr. Miyake.
“The center of gravity in South Korean domestic politics seems to be shifting from the left to center left. That is especially true among the younger generation,” he says. “Maybe five, 10 years ago anti-Japanese political slogans paid in South Korea, but not necessarily now.”
The Japanese public, while more ambivalent overall, has also grown more positive toward South Korea in the past decade. One poll shows the percentage of Japanese respondents saying they “like” South Korea nearly doubled from 10% in 2015 to 19% in 2025, and those saying relations between the two countries are going well increased from only 7% to 29%.
This stands in contrast to the deep freeze in relations as recently as 2018. That was sparked in part by historical grievances arising from Japan’s 1910 to 1945 colonial rule of Korea, including the mistreatment of Korean workers and of Korean women forced into sexual slavery by the Japanese military.
Previous leaders in Seoul and Tokyo have tried to improve ties. South Korean President Yoon Suk-yeol, who took office in 2022, broke the ice by meeting with then-Japanese Prime Minister Kishida Fumio in 2023. But Mr. Yoon was later impeached for his short-lived 2024 martial law declaration, and Mr. Kishida and his successor, Ishiba Shigeru, both resigned amid party scandals and low approval ratings.
Compared to their predecessors, Ms. Takaichi and Mr. Lee are in uniquely strong positions, politically, says Mr. Sneider. And at the same time, broader regional challenges have underscored the importance of their cooperation.
Strategic competition between the United States and China, Beijing’s military buildup and more aggressive posture in the region, and North Korea’s advancing nuclear weapons program have all increased the need for trilateral defense coordination between Japan, South Korea, and the U.S.
“We must ensure that our countries play a central role in maintaining stability in the Indo-Pacific region,” Ms. Takaichi told Mr. Lee this week.
The energy crisis created by the Iran war is adding fresh urgency to their coordination on economic issues, too. “Given the situation in the Middle East,” she stressed, “it is critically important that we build on the positive momentum between Japan and South Korea.”
At this week’s meeting hosted by President Lee, the two sides announced agreements to strengthen cooperation on oil and liquified natural gas supplies, as well as artificial intelligence, biotechnology, and cross-border crime.