Since the 2002 World Cup soccer tournament, many South Koreans have been watching European Football League games. Liverpool Football Club is one of the most popular in South Korea. But fans in Korea started turning their backs on the club after it posted a video that showed an image of the Rising Sun flag, a symbol of Japan’s imperialism, on the Liverpool FC’s official website.

South Koreans expressed anger at Liverpool’s behavior, and the club offered an apology. However, it published its apology on its Facebook page that can be seen only in Korea. On its official website, Liverpool didn’t issue any notice related to the Rising Sun flag.

Shortly after the apology appeared on Facebook, Liverpool’s official Japanese Twitter account shared another image of the Rising Sun flag, with club manager Jürgen Klopp holding the World Cup trophy. Many Koreans condemned Liverpool, judging that the club’s apology lacked sincerity. And, enraged at Liverpool’s posts, some Koreans mailed complaints to the soccer club.

South Koreans have often been frustrated whenever people portray the Rising Sun flag without any apparent understanding of what that flag means in modern East Asian history: as a symbol of Japan’s invasion of Asian countries and colonial rule in the early 20th century.

Since 1870, the Rising Sun flag has been used as a symbol of Japan’s imperialist army, starting with the invasion of Korea, then under the Joseon dynasty, a kingdom that lasted for five centuries. Later, Japan started to wield influence on the Joseon dynasty, colonizing the Korean Peninsula.

Until the end of World War Ⅱ, the Japanese imperial army used the flag. And now, the Rising Sun flag is the banner of the Japan Maritime Self-Defense Force.

For some Asian countries, the Rising Sun flag is still a reminder of Japan’s imperialism, invasions and wartime crimes, such as sex slavery and forced labor. Many Koreans argue that the Rising Sun flag is the Asian version of the Nazi Swastika. But as the Liverpool FC case showed, the world is still using the Rising Sun flag. While many countries denounce the atrocities of the Nazis, they sell and use products decorated with the Rising Sun, being misinformed about East Asian history.

That, however, is not the only problem. Japan itself is also using the Rising Sun flag, playing down its historic meaning. When it was revealed that Japan planned to use the flag during a national fleet review in 2018, both North and South Korea criticized the move.

Moreover, Japan wants to use the Rising Sun flag at the 2020 Tokyo Olympics. The South Korean Sports Ministry asked the International Olympic Committee to ban the flag from the Tokyo Games. As well, a lawmaker with the ruling Democratic Party said this symbol of imperialism was not proper to use at the Olympics, which aim to establish international peace.

Amid the controversy over the use of Rising Sun flag at the Tokyo Olympics, more than 48,000 people signed an online petition that urged the IOC to ban its use. The organizers of the Tokyo Olympics, however, have refused South Korea’s request.

Last month, the Japanese Foreign Ministry issued a notice in Korean claiming that the Rising Sun flag doesn’t represent Japan’s imperialism. But the ministry’s statement provoked criticism from its South Korean counterpart and from the Korean Central News Agency, the state news agency of North Korea.

Germany, which in the 1930s and 1940s invaded some European countries and committed the Holocaust, is still atoning for the Nazis’ crimes and imperialism. And the German Criminal Code outlaws the use of symbols that “describe unconstitutional organizations,” including Nazi symbols. Japan, however, denies the Rising Sun flag’s historical meaning.

For Koreans, use of the Rising Sun flag mocks its colonial history and even the victims of brutal wartime crimes. That’s why many Koreans are trying to reveal what the Rising Sun flag means, as well as urging a global ban on the flag.