His musical breakthrough came in 1990 with the release of his debut album, Loving You Forever, which rocketed him to stardom. Like the other "kings", Kwok has picked up many best-singer and best-performer awards in Hong Kong and also in Taiwan, where he was known for his Honda motorcycle TV commercials.

The birth of the "Four Heavenly Kings" was a milestone for Chinese pop music culture because these young men became the first idols, not just for Hong Kong music fans, but also for many mainlanders born in the 1980s.

Kwok was certainly the best dancer among them, but he does not want to reminisce and linger on days gone by.

"It's gone, and I don't want to look back. I love new challenging jobs," Kwok says. "And I am what I am now."

Now, it's all about films. "I have reached a certain level in singing what I am pursuing now is the feeling of acting," he says.

A major shift from music to film happened in 2006, when Kwok left Warner Music, where he had been contracted for 13 years, and signed with the Music Nation Group.

He felt his new label would allow him to "realize his years-long wish - acting in more better quality films".

When asked if he had met any difficulties in this new challenge, he said: "not at all", and then called it a "very natural" development.

Reiterating his love for new challenges, Kwok says he wants to act in "all the roles I've never tried before".

"People from all walks of life, no matter which role I act, I'll present it vividly on the screen," he adds.

His most recent movie reveals his plan to become more of a heavyweight. Kwok stars in Life for Love, a tragic love story about two AIDS-affected people. Kwok plays a primary school teacher who is sent from the city to teach in the countryside, contracts AIDS and later develops a crush on another AIDS patient, played by the mainland's biggest female movie star, Zhang Ziyi.

As more serious Chinese films roll into production Kwok is optimistic about the future of the industry and wants to be in the thick of the action.

"Many foreign investors now know the film industry is developing rapidly in China ... the future (of Chinese films) will be terrific," he says.

He says China has many "great actors" and "great directors", and singled out Jiang Wen, director of Let the Bullets Fly, as his favorite.

The comedy, released in December last year, grossed 730 million yuan (78.6 million euros) at the box office, becoming the highest-grossing domestic film in China's cinematic history. Despite being a megastar himself, Kwok respectfully calls 48-year-old director Jiang, "Teacher Jiang", and hopes to work with him in the future.

When asked to name the actor he wants to work with most, Kwok pauses for 30 seconds then says he has too many favorites, but names comedians Ge You and Zhao Benshan.

"But if I have to single out one actor in the Chinese world, I would say Chow Yun-Fat," Kwok stresses.

Chow, 56, from Hong Kong, is best known for his collaboration with filmmaker John Woo in heroic bloodshed genre films A Better Tomorrow, The Killer, and Hard Boiled; and to the West for his leading role in Crouching Tiger, Hidden Dragon.

Kwok and Chow recently worked together in The Monkey King, a Chinese 3D-Imax film to be released in July next year. Kwok says their cooperation was very brief, but he hopes to link with him more "on some other roles".

Talking about the future, Kwok continues to focus on acting but would not rule out directing some time down the track, especially "if there's a very good script in front of me".

"May not be now, as I think more personal experience and accumulation are needed to be a director. I am enjoying acting now, so I won't push myself," he says.