Tokyo (AFP) - Thousands of K-Pop fans flocked to a major concert by top South Korean music stars in Japan this week, with organisers and fans alike calling it a "bridge" for two nations locked in a never-ending diplomatic squabble.

The K-Pop juggernaut has been spreading around the world with South Korean music, television and movies making a big splash in countries with few ties to Seoul.

But the country's offerings are particularly loved across the sea in Japan whose own unique culture has long been a hit with South Koreans, despite historical animosities and territorial disputes.

That mutual love was on display in Yokohama, south of Tokyo, on Wednesday as a slate of acts including Supernova, teenage girl band sensation Crayon Pop and crooning boy band 2PM performed for screaming Japanese fans, including young girls and some middle-aged men.

Kurumi Hagi, a 17-year-old fan of 2PM, was among the 9,600 capacity crowd packed into the concert put on by popular South Korean music television show M Countdown.

"When I feel tired, I just need to see them to feel lively again," Hagi said. "Their performance gives me energy."

Another huge fan of the six-boy band is Hagi's mother, who landed a backstage pass, while 40-year-old Kan Yokoyama can't get enough of the group Girl's Day.

"I am totally hooked by Girl's Day," he said. "I met them at one recent fan meeting, and (band member) Hyeri showed me how to dance. She was so sweet, and I've been huge fan of her ever since."

The event was held as relations between Tokyo and Seoul are at their worst level in years, mired in emotive disputes linked to Japan's 1910-45 colonial rule, particularly Japan's use of South Korean "comfort women" as sex slaves in wartime brothels.

In an illustration of sensitivities, South Korea's national publicly-funded broadcaster KBS this week banned Crayon Pop's latest song because of a Japanese word contained in its lyrics.

- Musical diplomacy -

Hawkish Japanese Prime Minister Shinzo Abe last week held his first summit with South Korean President Park Geun-Hye, an occasion in the Hague hosted by US President Barack Obama, whose administration is increasingly frustrated by incessant sniping between its two major Asian allies.

Park stood stone-faced at a press conference where Abe tried his hand at speaking Korean, and one-on-one talks appear a long way off.

A dispute over islands in the Sea of Japan, which Koreans call the East Sea, and Abe's tendency to flirt with historical revisionism have also aggravated tensions. Demonstrations by Japanese far-right nationalists against Koreans living in the country are another distraction.

But the concert's organiser said South Korea's spreading of so-called soft power through music and pop culture could help bring the combative neighbours together.

"Since we are a cultural industry company, we believe we can do something small that government won't and can't do," said Shin Hyung-Kwan, executive producer of CJ E&M's music channel Mnet.

"So, in that respect, when there is political tension ... we believe cultural exchanges can shorten the distance between the two nations."

Girl's Day fan Yokoyama agreed: "In order to move forward, we get together on things like this. If we keep digging deep into the past, our interests will always end up clashing."

And with the surging popularity of all things South Korean, there seem to be few limits to the appeal of its pop culture idols as they take on the world.

"In South Korea, idols have become multinationals because the industry is targeting not only the domestic market, but also foreign markets," said 2PM member Ok Taecyeon.

"They're modelled in a way they can be popular not only in Asia, but also around the world."