But in an era of globalised businesses and transnational brands, determining where a product originates or a company’s national identity is easier said than done – leading to confusion over what, exactly, consumers should be boycotting.

A common refrain, as expressed by 21-year-old university student Kim Dae-young, is “if it sounds Japanese, it’s probably Japanese”. Yet the truth of the matter is not so simple.

In South Korea, many seemingly foreign brands are in fact owned and operated by local companies, at least in part.

But South Korean conglomerate Lotte actually owns a 49 per cent stake in the clothing brand’s local parent company, Fast Retailing Korea – as well as a 40 per cent stake in the Korean iteration of Japanese lifestyle brand Muji, known for its quintessentially minimalist aesthetic.

Lotte itself is no stranger to controversy when it comes to the long-standing rivalry between South Korea and Japan. Though the conglomerate – which has an interest in everything from food and housing to amusement parks in South Korea and employs more than 60,000 people worldwide – calls itself Korean, it first launched in Tokyo in 1948 before expanding to the homeland of its founder, 96-year-old ethnic Korean Shin Kyuk-ho.

Shin, who is known as Takeo Shigemitsu in Japan, was born in Korea during the period of Japanese occupation from 1910-45. Educated in Tokyo, he made his fortune in Japan and founded Lotte before returning to the country of his birth.

Many in South Korea remain suspicious of its origins, however, and have in the past accused the firm of being a Japanese company in all but name.

Kim, the university student, noted that the eldest son of Lotte’s founder, Shin Dong-joo, “speaks Korean rather poorly with a Japanese accent” – a trait that “bought him no public sympathy” when he and his brother fought for control of the company in 2012.

“Even though it is … a multinational brand as the name suggests, people seem to identify companies under a ‘single national origin’,” Kim said, adding that other conglomerates with simpler origin stories, such as Samsung, will always be considered Korean.

The antagonism between South Korea and Japan stretches back decades, much of it stemming from the Japanese colonisation of the Korean peninsula at the start of the 20th century.

Recent disputes range from Tokyo’s refusal to acknowledge the sexual enslavement of Korean “comfort women”, to the ownership of a group of disputed islets in the waters between the two nations.

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Yet the two nations have shared thousands of years of interaction, with myriad examples of cross-cultural exchange and economic cooperation.

Take discount goods chain Daiso, for example, which South Korean media has described as the country’s No 1 retailer, with many Koreans visiting several times a week.

Like Lotte, its history is complex – first having appeared in South Korea during the 1990s under a different name, before rebranding after entering into a joint venture with Daiso Japan.

Today, Korean company Asung HMP holds a majority stake in Daiso Korea, with a little more than half of the shares, while Japan’s Daiso Industries owns about 34 per cent.

Its product lines are equally hybrid, featuring both Japan and Korea-designed lifestyle items, the bulk of which are now manufactured in China. Daiso Korea also features a logo that is distinctly Korean and notably different from the original Japanese one.

“Daiso Korea is independent from Japan. A Japanese company has a 34 per cent stake in Daiso Korea,” wrote Twitter user Hong Cho. “Please only boycott products with a Daiso Japan logo on the price tag.”

Justin Shin, a Seoul-based photographer and fashion and lifestyle branding expert, said Koreans have a strong sense of what is made in Korea and what is made in Japan.

“When it comes to product style and appearance however, Japanese style has deeply influenced Korea for decades and this has been reinterpreted many times … So in that sense, Koreans may have hard time distinguishing and segregating Japanese and Korean products,” he said.

Indeed, helping consumers distinguish between Korean and Japanese products is keeping local retailers busy and in business. Stationary and book store Kyobo Hottracks began labelling domestically produced pens with the Korean national flag or flower, according to AFP. Sales for Korean pens increased by 23 per cent that same week, while Japanese products fell by 10 per cent, according to the same report.

Meanwhile convenience store owners and local bars have removed all traces of formerly popular Japanese beers including Asahi, Kirin, Sapporo and Suntory – sales for all of which fell by about 25 per cent in the first two weeks of July, AFP reported. A local grocery store association has said 3,700 of its members will no longer order Japanese products, according to AFP – with many such shops around South Korea now carrying signs citing that they will no longer sell Japanese goods.

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Further complicating matters are other non-domestic brands that Koreans have long though of as their own.

“Instead of Uniqlo, there’s good clothing from Redface, BlackYak, K2, Crocodile … all domestic brands,” wrote Korean Twitter user @MetalMeal – yet Crocodile, which operates stores all over South Korea and was once embroiled in a trademark dispute with French company Lacoste over its similar logo, is in fact a Hong Kong company.

If anything, such misidentification and confusion over brand identities demonstrates how a company’s origins are no longer of relevance today, according to Yves Tiberghien, political scientist and director emeritus of the Institute of Asian Research at the University of British Columbia.

“Consumer tastes and preferences have really converged between Korea and Japan. The production chains, networks and marketing strategies are intertwined so the outcome is that it is impossible to disentangle the production networks, marketing and eventual products,” he said, adding that Daiso was a “case in point”.

“Consumers cannot know indeed which parts are Japanese and which parts are Korean.”

Even if a product has the “flavour” or appearance of a certain country, most are in fact hybrids made up of an integration of different components sourced from all over the world, Tiberghien said.

He gave the example of Line, Japan’s most popular messaging app, which despite being developed by the Tokyo-based Line Corporation, is ultimately owned by Korean internet giant Naver.

“Line is Korean and all the data from Japanese users may transit through Korea,” said Tiberghien. “I don’t think Japan knows that. But if they did, they would be more aware of how interconnected they are.”