President Trump poses with Japanese Prime Minister Shinzo Abe, right, and South Korean President Moon Jae-in at the U.S. Consulate General in Hamburg in July. Trump begins a trip to Asia on Friday, leading off with visits to Tokyo and Seoul. (Evan Vucci/AP)

When he arrives in Tokyo on Sunday, President Trump will eat lunch with Japanese Prime Minister Shinzo Abe before the pair play nine holes together at a fancy golf club that only recently allowed women to become full members. Afterward, they'll enjoy a private dinner — featuring steak, Trump's favorite.

When the U.S. president gets to Seoul on Tuesday, however, it’s a different story. Although it’s a state visit, he’ll have time only for a cup of tea with President Moon Jae-in in his office before their protocol-laden state dinner.

Trump’s varied itineraries in Japan and South Korea reflect a broader discrepancy in his ties with the two U.S. allies’ leaders.

“He has his BFF here in Japan, but with South Korea — he hasn’t gone full-bore like he has on the Mexican leader, but he definitely has a more contentious relationship,” said Jonathan Berkshire Miller of the Japan Institute of International Affairs in Tokyo.

Trump is scheduled to spend 48 hours in Japan and 24 in South Korea during his 12-day trip to Asia. That disparity, coupled with Trump's punchier statements on the South, "does seem to kind of send a bit of a message," Miller said.

Trump repeatedly criticized both Japan and South Korea on the campaign trail, wondering why the United States was paying to defend two rich countries and throwing trade deals with both into doubt.

After the November election, Abe wasted no time in trying to win over the incoming president, immediately heading to New York to meet Trump, with a $3,755 golden golf club as a present.

“Abe assessed this alarming situation and took very deliberate steps to establish a relationship with Trump early on, making a clear case for the importance of Japan to U.S. interests and appealing to Trump on a personal basis,” said Kristi Govella, a fellow in the program on U.S.-Japan relations at Harvard University.

Since that first encounter, the two have met in person seven more times and spoken on the phone at least 14 times.

At those meetings and after missile launches and September’s nuclear test, Abe has made a point of wholeheartedly agreeing with Trump on taking a hard line against North Korea. It is only on the Trans-Pacific Partnership, the Pacific Rim trade deal from which Trump withdrew, that they have publicly diverged.

At a meeting during the U.N. General Assembly in September, Trump praised Abe for “doing a wonderful job, doing a great job for the people of Japan.” Abe, in turn, called his American counterpart “Donald” twice — a striking familiarity for etiquette-bound Japan.

South Korean university students protest the U.S. president’s upcoming visit during a rally in front of the National Assembly building in Seoul on Friday. (Yang Ji-woong/European Pressphoto Agency-EFE/REX/Shutterstock)

Abe’s close relationship with Trump comes at a cost, said Jeff Kingston, director of Asia studies at Temple University’s campus in Japan.

“This bromance is based on total deference and subordination. Abe is trying to avoid saying anything uncomfortable,” Kingston said. “With Trump, you’re only one tweet away from being excommunicated.”

But during the first four months of the Trump administration, South Korea was in a state of political limbo while its then-president, Park Geun-hye, was being impeached. As a result, while North Korea fired off missiles and threats, Trump often overlooked South Korea and talked instead with Japan and China.

South Korea’s sensitivity to that tendency, widely labeled “Korea passing,” reflects its long-held fear of being seen as playing second fiddle to Japan, its former colonial master and continuing rival.

Since he was elected president in May, Moon has met with Trump on several occasions and the White House has emphasized the importance of the security alliance with South Korea. But the two have not hit it off in the way Trump and Abe have.

That is only partly because of personal style. Abe and Trump are conservatives who have taken a hard line on North Korea, while Moon is a liberal who favors engagement with Pyongyang and opposed deployment of a U.S. antimissile battery in the South. In September, Trump criticized the South Korean's "talk of appeasement" in a tweet.

“Moon’s leadership style is quite different from Trump’s, and their connection has been more tentative,” Govella said. “This difference in personal relationships seems to correlate to a difference in diplomatic relationships. We see Trump following through on his campaign rhetoric much more with Korea than with Japan.”

The U.S. president has threatened to tear up a trade deal with South Korea that had seen the country gain an advantage on Japan, which doesn’t have a bilateral pact with the United States. The move was halted only by a North Korean nuclear test in September.

Some South Koreans wonder whether “Korea passing” is still going on, even now that they have a president in place, citing the time Trump will spend in Tokyo compared with Seoul.

Ahn Cheol-soo, who ran for president against Moon, has said that the difference means South Korea has “lost face” and that Trump’s short visit does not befit a “dignified country.”

"Many negative side effects are expected," Ahn told his centrist party's members, according to local reports.

Still, this will be the first state visit to South Korea by an American president in 25 years. Trump will attend a state dinner — compared with a regular banquet in Japan — and visit Camp Humphreys, south of Seoul, the largest American military base outside the United States and one to which South Korea has contributed more than half the cost.

"This is a state visit, and the South Korean government will show that South Korea is a great partner in the alliance," said Cho Byung-jae, a former adviser to Moon who now heads South Korea's diplomatic academy.

Trump will also become the first U.S. president in a quarter-century to deliver a speech in the National Assembly. But some South Korean officials are worried about what he might say.

“Normally, when a U.S. president comes to give a speech, they compare notes with the South Korean government,” said Lee Seong-hyon, a research fellow at the left-leaning Sejong Institute. “Trump’s speechwriters may have given him advice, but it’s still Trump. He could go off-script.”

Either way, protests are expected in Seoul, with a “No Trump, No War” rally scheduled for Saturday, amid anger and confusion over Trump’s repeated threats to take military action against North Korea.

A recent Pew poll found that more than three-quarters of South Korean respondents consider Trump "dangerous."

"Honestly, Trump is not very popular in South Korea," said Han Jae-ho, a 20-year-old student. "But I'm expecting him to show a new side in South Korea and work hard for a better relationship with South Koreans."

Big protests could backfire for Moon’s government, said David Straub, a former State Department official and the author of a book on anti-Americanism in South Korea.

“I think the South Korean leadership and many South Korean intellectuals are hoping very, very much that Trump will come away from the visit feeling that South Korea is a good ally and that he has to be careful about threatening war against North Korea,” Straub said. “They don’t want things like protests gratuitously offending him.”

Even if Trump is affronted, does the difference in his personal relationships with the Japanese and South Korean leaders matter to the United States’ security alliances with each country, both born out of World War II?

Hard to say, said Harvard’s Govella. “Within the U.S. government, there is strong consensus on the importance of both alliances to American strategic interests in Asia, and given Trump’s focus on North Korea, the cooperation of both Japan and South Korea will be essential to any goals that he hopes to accomplish.”

Taylor reported from Seoul. Yoonjung Seo in Seoul contributed to this report.

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