NAHA, Japan » In a windowless room in a corner of a bustling market where stalls displayed severed pigs’ heads and bolts of kimono silk, Okinawans gathered to learn about a political idea that until recently few had dared to take seriously; declaring their island chain’s political independence from Japan.

About two dozen people of all ages listened as speakers challenged the official view of Okinawa as inherently part of homogeneous Japan, arguing instead that Okinawans are a different ethnic group whose once independent tropical islands were forcibly seized by Japan in 1879. Then, to lighten the mood, the organizers showed "Sayonara, Japan!", a comedy about a fictional Okinawan island that becomes its own little republic.

"Until now, you were mocked if you spoke of independence," said one speaker, Kobun Higa, 71, a retired journalist whose book on the history of the tiny independence movement has become a hot seller online. "But independence may be the only real way to free ourselves from the American bases."

Higa and other advocates admit that few islanders would actually seek independence for Okinawa, the southernmost Japanese island chain, which is home to 1.4 million residents and more than half of the 50,000 U.S. troops and sailors based in Japan. But discontent with the heavy U.S. presence and a growing perception that the central government is ignoring Okinawans’ pleas to reduce it have made an increasing number of islanders willing to at least flirt publicly with the idea of breaking apart in a way that local politicians and scholars say they have not seen in decades.

In May, a newly formed group led by Okinawan university professors held a symposium on independence that drew 250 people. A tiny political party that advocates separation from Japan through peaceful means has been revived after decades of dormancy, though its candidates have fared poorly in recent elections. And on his blog, a member of Parliament from Okinawa recently went so far as to post an entry titled "Okinawa, It’s Finally Time for Independence From Yamato," using the Okinawan word for the rest of Japan.

"Before, independence was just something we philosophized about over drinks," said Masahide Ota, a former governor of Okinawa, who is not a member of the movement. "Now, it is being taken much more seriously."

The independence movement remains nascent, with a few hundred active adherents at most. But Ota and others say it still has the potential to complicate Japan’s unfolding contest with China for influence in the region.

That struggle expanded recently to include what appears to be a semiofficial campaign in China to question Japanese rule of Okinawa. Some analysts see the campaign as a ploy to strengthen China’s hand in a dispute over a smaller group of islands that has captured international headlines in recent months. Some Chinese scholars have called for exploiting the independence movement to say there are splits even in Japan over the legitimate ownership of islands annexed during Japan’s imperial expansion in the late 19th century, as Okinawa and the smaller island group were.

Okinawa has long looked and felt different from the rest of Japan, with the islands’ tropical climate, vibrant musical culture and lower average incomes setting it apart. Strategically situated in the center of East Asia, the islands, once known as the Kingdom of the Ryukyus, have had a tortured history with Japan since the takeover, including the forced suicides of Okinawan civilians by Japanese troops during World War II and the imposition of U.S. bases after the war.

For years, Okinawans directed much of their ire over the bases at the United States. But that changed four years ago when the Japanese prime minister at the time, Yukio Hatoyama, reneged on campaign pledges to move the bustling Marine air base at Futenma off Okinawa, rather than to a less populated site on the island as previous governments had approved. After that, many Okinawans shifted much of their anger toward the rest of Japan, which wants the U.S. military presence to offset China’s growing power, but is unwilling to shoulder more of the burden of bases for fear of crime, noise and accidents.

Local leaders and scholars say the last time Okinawans spoke so openly of independence was during a period of sometimes violent unrest against U.S. control before the United States ended its postwar occupation of the islands in 1972.

"There is a growing feeling that Okinawans just exchanged one colonial master in Washington for another one in Tokyo," said Shinako Oyakawa, 32, a doctoral student at the University of the Ryukyus and a co-founder of Okinawan Studies 107, a group promoting research into Ryukyuan ethnic identity.

Such discontent has helped nurture groups like hers, which seek to promote the idea that the islanders form a distinct ethnic group. It has also led to the creation of places like Ryukyu Hall, a privately run school that opened last year and offers classes on Okinawan language and culture.

On a recent weekend, about 30 people gathered at the school, a small, sparsely furnished two-story building, to hear accounts in the Ryukyuan language by survivors of the U.S. invasion of Okinawa in 1945.

"Regaining our identity is the first step toward regaining independence," said Midori Teruya, 41, a co-founder of the school in Ginowan, the site of the Futenma air base.

The talk of independence has grown enough that it is being heard in Tokyo, where some conservative newspapers have begun calling the Okinawan independence activists "pawns" of China.

Whether or not the activists are pawns, there is certainly some discussion in China about using the independence movement. Recently, an editorial in The Global Times, a state-run Chinese newspaper, said China could pressure Japan by "fostering forces in Okinawa that seek the restoration of the independence of the Ryukyu chain."

Few believe China is about to pursue ownership of Okinawa. But Japanese analysts see the informal campaign as the latest gambit in China’s attempts to take over the smaller group of islands, known as the Senkaku in Japan and Diaoyu in China, by essentially warning that China could expand its claims beyond those islands if Japan ignores its arguments.

"It will create problems for us if the Chinese government tries to use this issue," said Masaki Tomochi, a professor at Okinawa International University who helped organize the symposium on independence in May.

Tomochi and other activists said that in the remote event that Okinawa became independent, they felt little fear of a Chinese takeover because the Ryukyus had held friendly ties with China for centuries before the Japanese takeover.

Tomochi’s group is planning a second symposium to present research on how small Pacific island nations like Palau could serve as a model for a future Ryukyu republic. The idea is to try to overcome what he sees as the main challenge his movement faces: winning over Okinawans who seem basically content with their Japanese-style living standards.

"People are talking independence now, but how realistic is it?" asked Yoshinao Hiyane, 22, an economics major at Okinawa International University. "My generation has grown up Japanese."

At the movie screening in the market, independence supporters tried to bolster the notion that their idea is more than a fantasy by handing out color-copied "currency" of a Ryukyu republic. They stood before a blue banner with three stars that the organizer, Chosuke Yara, called its flag.

"Recently, the interests of the Japanese people and the Ryukyu people have clearly diverged," said Yara, 61, the head of the tiny Ryukyu Independence Party. "Independence is an idea whose time has come."

© 2013 The New York Times Company