Hong Kong, China - Visitors arrived to the chants of protesters who wore white shirts and blue hats and carried signs reading: "Uncover the hidden truth" - urging passersby to learn the "real history". But these protesters couldn't stop the grand opening of Hong Kong's controversial June 4 Memorial Museum on Saturday. Sponsored by the Hong Kong Alliance in Support of the Patriotic Democratic Movements of China (the Alliance), the museum documents the 1989 clash between Chinese government forces and student protesters that killed hundreds and wounded thousands more in Beijing's Tiananmen Square.

It is the world's first permanent museum dedicated to the deadly protests, and recent tensions between pro-democracy groups and communist government supporters in Hong Kong have thrust the facility into the middle of current debates.

"A lot of people have forgotten what has happened and mainlanders are not allowed to remember," Cheuk-yan Lee, chairman of the Alliance told Al Jazeera. In Beijing, where Tiananmen Square serves as a major tourist site featuring historical depictions of the country's communist revolution, it is forbidden to discuss the landmark in relation to the events of 1989.

Inside the new 800-square-foot (74sqr m) museum, the dark red and black walls showcase a collection of written documents, reportage and nearly 1,000 archival photographs. Artifacts, including a bullet-riddled helmet worn by a student protester, have been collected to preserve the scarce physical history that remains 25 years after the event. The museum also sells USB sticks containing historical documents about the Tiananmen Square protests, which, organisers said, would be easier for mainland tourists to sneak through Chinese immigration.

Dramatic opening

At the opening, museum staff and supporters sparred verbally with protesters - the former group calling for an end to China's one party rule, while the later carried photographs of Chinese police officers injured in Tiananmen Square, accusing the Alliance of spreading misinformation. Altercations between the two sides forced Hong Kong police to call in reinforcements.

"This museum will attract the general public and is a means to educate the younger generation," said Johnny Lau, 60, a freelance journalist who reported from Tiananmen Square in 1989 before being banned from mainland China.

The (Tinanmen Square incident) is sensitive and contentious. We are afraid the museum will bring us trouble. - Yeung Cho-ming, secretary-general of Chiu Chau Plastic Manufacturers Association

The Alliance, founded in May 1989 by dissidents forced out of mainland China together with pro-democracy supporters in Hong Kong, has sponsored annual vigils for the victims of Tiananmen Square. The new museum, partially financed by $774,000 in donations, follows positive reaction to the Alliance installing temporary memorials in the past two years in Hong Kong.

The museum's impending opening sparked fierce debate between pro-democracy supporters and pro-communist groups in Hong Kong, over a chapter in history that pro-Chinese factions would like to forget.

But a more direct threat came from other tenants at the Foo Hoo Centre, where the museum is housed. Two companies threatened legal action, citing violations of the property deed and anticipated disturbance caused by a high volume of visitors.

"The (June 4 incident) is sensitive and contentious. We are afraid the museum will bring us trouble. Someone might protest here and affect our daily operations," Yeung Cho-ming, secretary-general of Chiu Chau Plastic Manufacturers Association, an organisation which rents space in the building housing the museum, told the South China Morning Post, a Hong Kong-based English newspaper.

Civil liberties in Hong Kong were largely preserved upon independence from the British in 1997, making the quasi-autonomous territory a suitable home for projects such as the memorial museum. The Alliance also took geography into consideration when selecting Hong Kong's Tsim Sha Tsui neighbourhood as its home.

"It is a place where there are lots of mainland tourists," Lee told Al Jazeera. In the short walk from the nearest subway to the museum, visitors might take Nathan Road, which bisects what was once the densest place on the planet and showcases both authentic restaurants serving mainland Chinese fare as well as luxury Western brands which now benefit from the growing purchasing power of China's middle class - in particular the 45 million mainland tourists expected to flock to Hong Kong this year.

Regional tension

Tsim Sha Tsui, located in the Kowloon region, provides a glimpse of how mainland China has been grafted into contemporary Hong Kong. The influx of mainlanders has driven up prices for essentials such as milk powder and baby formula and inflated property costs. According to Hong Kong's Census and Statistics Department, visitors from mainland China accounted for 57 percent of all tourist spending in 2012, up from 33 percent in 1999. Today, the museum serves as a lightning rod for growing concerns over China's political and economic impact in Hong Kong.

You never can compare Hong Kong to anywhere else in China. No one country has successfully had one democratic system and one non-democratic system at the same time. - Jieping Zhang, author

"There is a lot of tension between those in Hong Kong and visitors from the mainland,"said Lee, who is also a legislative council member in Hong Kong's New West Territories. One recent spat, which made national headlines, involved a young, visiting Chinese boy urinating in public. "We cannot accept the behaviour of the tourists or the fact that they are changing the landscapes of our city," Lee said.

"People just don't understand each other," said Jieping Zhang, author of A Year in Wukan to be published this June, which documents that village's 2011 struggle for democracy against the Chinese government. "Both the people of Hong Kong and mainland China don't have complete information, due to the Chinese government's control, so they fight over unbelievably simple questions without the proper context."

This week, Chinese Vice President Li Yuanchao denounced the pro-democratic Occupy Hong Kong Movement, telling reporters at Hong Kong's Ta Kung Pao, a newspaper affiliated with the Chinese government, the protests "would delay universal suffrage and wreck the prosperity and stability of Hong Kong".

One potential flashpoint in this relationship is the impact Beijing might exert in the election for Hong Kong's next chief executive in 2017.

"There has long been a worry about Beijing and those who support the central government working to slowdown the moves towards fuller democratisation and limit the amount of freedom of speech and assembly that [makes Hong Kong] so different from most other parts of the country," said Jeff Wasserstrom, Chancellor's Professor of History at UC Irvine and author of China in the 21st Century: What Everyone Needs to Know.

For Zhang, who has reported extensively on the Chinese government's willingness to permit the democratic process within its territory, Hong Kong retains a unique status.

"You never can compare Hong Kong to anywhere else in China," she said. "No one country has successfully had one democratic system and one non-democratic system at the same time. If Hong Kong established that democratic system, it would be the first of its kind and China won't let that happen."

Tim Summers, a Senior Consulting Fellow for Chatham House, said the tensions between Hong Kong and China cannot be simplified to a debate between those for or against democracy. Instead, these anxieties are facets of an ongoing negotiation about how far or deep the democratic process might extend.

"We're talking about a constitutional arrangement where Beijing appoints Hong Kong's chief executive," Summers told Al Jazeera. "The question is how democratic can Hong Kong be while still making the arrangement work politically for the parties involved."

For the Alliance, these facts only heighten their belief that pro-democratic movements - and projects like the June 4 memorial museum - are critical for coexistence in the future.

"It isn't about spreading hatred towards mainland Chinese, but about sharing our experience, our values, our manners, rule of law, freedom and democracy," Lee said.