South Korea and Japan are engaged in an unrelenting trade war, which has seen both sides curb vital exports and remove each other as preferred trading partners.

The feud is reigniting more than 100 years of tension between the two nations, which involved Japan colonizing Korea in the early 1900s and using forced Korean labor during World War II.

Many South Koreans are now punishing Japan by boycotting its goods, and local businesses are posting signs barring Japanese people from entering or ensuring customers that no Japanese goods are on sale.

One South Korean told Business Insider she canceled a long-awaited trip to Japan with her friends and planned to take a staycation instead.

Another citizen told Business Insider that the protests would only make Japan-South Korea relations even worse.

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JEJU, South Korea — South Koreans are demonstrating en masse, boycotting Japanese goods, and canceling their trips to Japan to strike a blow in an increasingly bitter trade war between the two nations.

South Korea and Japan are engaged in a massive trade spat, which has seen the two countries remove each other from their "white lists" of preferred trading partners.

It came after Japan in July placed restrictions on the exports of semiconductor materials key to South Korea's manufacturing industry, which was widely seen as retaliation over a Supreme Court ruling last year calling on Japanese companies to pay compensation for their use of forced labor during Japan's occupation of the Korean Peninsula from 1910 to 1945.

Since then, a vocal group of South Koreans have called for a boycott of all things Japanese — and it seems to be working.

An anti-Japan sign that says "No Abe" — referring to Japanese Prime Minister Shinzo Abe — at a protest in Seoul, South Korea. Komeil Soheili/Business Insider

Jayeon, a real-estate employee in Seoul, and seven of her high-school friends just canceled a flight to Japan despite having booked their hotels and planned their trip for about a year.

The group of 60-somethings had been hoping to celebrate their reunion in Japan but felt they had to stand up to Japan and support the growing protest movement.

To Jayeon, Japan is a country that's opting to harm South Korea's economy instead of apologizing for its colonial history. She and her friends now plan to travel within South Korea instead.

"Of course we love many things of Japan, and that's why we wanted to travel there together with my best friends. Japanese food, anime, comic books, movies, and music were around us since childhood," she told Business Insider.

A sign outside a ramen shop in Seoul, which says in black: "100% pure Korean original corporation." The words in red say: "Don't worry, there is no loyalty or extra fee to Japan at all. Nothing goes to Japan!" Komeil Soheili/Business Insider

But all these cultural influences weren't enough to stop her from joining the anti-Japan movement.

"As a Korean, I feel responsible for how people of my country think and decide. Japan has so many good things and we appreciate it, but we want a sincere apology for what they did with our women during the Second World War," she said, referring to the thousands of Korean sex slaves who Japanese troops used during wartime.

"If they won't accept their mistake and simply being sorry for that, how we can be sure that it will never happen again in the future? Now they even made another step forward and started a trade war against us. We are simple citizens, but canceling our travel to Japan and boycotting their products are the least we can do for now."

An anti-Japan protest in Seoul. Komeil Soheili/Business Insider

Jayeon knows that canceling a single trip won't change much, but if more and more people join the protest, they'll be able to send a message to Japan, she told Business Insider.

"It's a small fee we can give for our country," she said, referring to the fee for canceling her flights to Japan.

An anti-Japan protest in Seoul. Komeil Soheili/Business Insider

She, like her friends, she said, has also decided to stop buying anything Japanese until the two governments resolve their conflict.

"We haven't forgotten the sad history of our country and what Japanese did to us," she told Business Insider. "The fire was under ashes since World War II, and sooner or later Japan should have faced it."

"Honestly, I wasn't that sure at the beginning," she said, referring to her boycott of Japanese goods. "But my friends convince me that it's better we do something and not our government."

"We can live with Korean products as well," she added. "There are so many options — we just should choose other products. Sometimes we need to make a big change by doing small things."

An anti-Japanese sign outside a traditional house in Bukchon Hanok Village, a Korean traditional village in Seoul. The Korean words read: "No entry for visitors." Business Insider has blurred the house's telephone number. Komeil Soheili/Business Insider

No to Japanese holidays, beers, or movies

Jayeon is one of many thousands of Koreans around the country who have been boycotting all things Japanese since July. As both nations' governments refuse to back down in the trade war, neither are South Koreans.

Anti-Japan slogans and banners can be found almost anywhere in South Korea. Many organizations display banners that say "NO Japan" in front of their doors.

Convenience stores don't sell Japanese beers anymore, with South Korea's Hankyoreh newspaper reporting that sales of Japanese beer from July 1 to July 18 were 30% lower from the same period last year.

Some 447,000 Koreans boarded Japan-bound flights August 1-9, down 17.9% over the same period last year, The Korean Herald newspaper reported, citing government data.

Japanese stores are also empty, with The Korean Herald citing two women near Gwanghwamun Square in central Seoul as looking into the display window of Japan's Uniqlo clothing store and walking away, saying: "Yes, they are pretty, but we should not buy anything here."

Read more: South Korea and Japan are having their own trade war, and it's gotten so bad that some South Korean gas stations are refusing to refuel Japanese-made cars



A sign at a convenience store in Seoul listing the countries of origin of the beers on sale. Imported Japanese beer used to be very popular at the store, but it has now stopped selling it. Komeil Soheili/Business Insider

Not all South Koreans support the movement

In Jeju, one of the closest South Korean cities to Japan, signs of the anti-Japan movement were almost everywhere, particularly around its City Hall.

But not all South Koreans support the boycott-Japan movement.

Minkyeong, a high-school art teacher in Jeju, told Business Insider that while she wasn't happy with Japan's actions, boycotting its goods and services would only harm South Korea more.

"I totally understand why my friends decided to boycott Japan, but I can't agree with them," she told Business Insider, adding that she was the only one who felt so in her friend group. "Even though personally I want to do something in support of the suffering of our contemporary history, boycotting can't be a wise idea in the long term."

Japanese Prime Minister Shinzo Abe and South Korean President Moon Jae-In at the G20 leaders summit in Osaka, Japan, on June 28. Kim Kyung-Hoon/Reuters

"Whatever happened in history, we shouldn't forget and we need to keep the fight for it," Minkyeong said. "But we must not forget we are neighbor countries now and we do need each other."

"Korea is between Japan and China, and the USA plays a big role here as well," she added. "We are such a small country and can easily be a playground for other powers. I hope people see things more wisely and not affected by social-media trends easily."

"We built up our country from the ashes of war to one of the leading economic powers of the world," she said. "This couldn't happen if we made our neighbor country as an enemy. We already have one in the north, and that's really more than enough!"