Japanese publication Asahi Shimbun reports that Osaka, one of the largest cities in Japan, will throw out its sister city designation with San Francisco in protest over a Chinatown statue that honors human trafficking victims of the Second World War.

According to the newspaper, Osaka Mayor Hirofumi Yoshimura complained that, in light of statue installation, “Our relationship of trust was completely destroyed,” adding, “I will dissolve the sister-city relationship.”

Private groups financed and erected the Chinatown statue, entitled Women’s Column of Strength, and installed it in September in the new rooftop extension of St. Mary’s Park.

But the work, featuring three females holding hands, sits on public ground, and the Board of Supervisors unanimously voted in favor of its addition in 2015.

Carmel artist Steven Whyte crafted the edifice, which bears the inscription at its base:

This monument bears witness to the suffering of hundreds of thousands of women and girls euphemistically called 'Comfort Women,' who were sexually enslaved by the Japanese Imperial Armed Forces in thirteen Asian-Pacific countries from 1931 to 1945.

There are at least 10 similar monuments to World War II sex trafficking victims in the Untied States, but none in cities as high profile as San Francisco.

Mayor Yoshimura warned in September that he may “rethink” Osaka’s relationship with SF in light of the unveiling, which he believes unfairly singles out Japan for its war crimes.

San Francisco has 18 sister cities worldwide, ranging from Paris to Manila; however, Osaka was the first, establishing a relationship with SF in 1957. Washington Post notes that the sister cities designation was a diplomatic experiment to foster goodwill in the post-war years.

During World War II, Bay Area shipyards and factories produced 1,400 ships and hundreds of tanks for use in the Pacific conflict, and nearly 1.65 million soldiers shipped out for Pacific service from San Francisco.

Meanwhile, Osaka was one of Japan’s major industrial and commercial hubs during the war, and American air raids destroyed a third of the city and killed an estimated 10,000 civilians. The gesture of friendship between the two cities a mere 12 years later was poignant at the time.

Technically, losing the tie to Osaka won’t have much immediate, material effect. But it might translate into diminished business and political opportunities with Japanese interests in the future.