Gaming fans in Hong Kong have labelled as "absurd" a decision by Japan's Nintendo to rename the popular Pokemon character Pikachu using the official language of mainland China instead of local language Cantonese. 

Their fury taps into concerns in the semi-autonomous city that its Cantonese culture is being eroded as Beijing's influence grows. 

Hong Kong fans said they were insulted when Nintendo -- which makes the Pokemon franchise -- decided to unify all local translations of many Pokemon characters into Mandarin for the Chinese market, prompting a small protest at the Japanese consulate this week.

Previously, different Chinese markets had their own names for characters.

Mandarin is the main language of mainland China, but in Hong Kong, Cantonese is predominant.

Pikachu, a yellow creature with pointed ears and lightening bolt-shaped tail, used to be called "Bei-Ka-Chiu" by Hong Kongers, but the new official name has become Pikaqiu which would sound "Bei-Ka-Jau" in Cantonese.

More than 6,000 fans in Hong Kong have signed a petition which has been sent to Nintendo management in Japan. 

"The absurd replacement... will be like changing "Pikachu" to "Pikayau" in English -- who is willing to pay for something they don't recognise at all? If this is to happen, the sales of the series in Hong Kong are likely to suffer," the letter said. 

One campaign group member who did not want to be named said he felt the decision did not respect local culture and that his childhood memories had been ruined. 

"It's hard to believe it will be changed... we just want our local name back," he said. 

There is also now a question over an upcoming video game contest based on the cartoon, to be held in Hong Kong. 

Nintendo's Hong Kong branch said on Facebook late Tuesday that it is "reviewing" the arrangements for the city's leg of the international Pokemon World Championships, to take place later this month, and that it could be cancelled. 

It did not give a specific reason, saying there were "a range of factors".

Language has become an increasingly sensitive issue as concern grows that Beijing is trying to stamp out local culture.

In February, 10,000 people made complaints to the authorities after an evening news programme given in Mandarin began to use simplified Chinese as subtitles.

The city uses "traditional Chinese", a more complex set of characters, whereas "simplified Chinese" is more popular across the border.

There are also fears Cantonese is being sidelined in schools to make way for Mandarin under pressure from the authorities, thus risking the city's identity. 

Hong Kong was returned by Britain to China in 1997 and its liberties are guaranteed under a 50-year agreement but there are increasing concerns that they are under threat.