* Martial arts drama "The Grandmaster" kicks off Berlin
* Matt Damon, Anne Hathaway among stars on red carpet
* Film festival showcases banned Iranian director Panahi (Adds quotes, details, description)
By Mike Collett-White
BERLIN, Feb 7 (Reuters) - The 2013 Berlin film festival kicks off on Thursday with the red carpet premiere of "The Grandmaster", Hong Kong director Wong Kar Wai's martial arts period drama set in China at the time of the Japanese invasion in the 1930s.
Starring regular collaborator Tony Leung Chiu Wai as kung fu master Ip Man and Zhang Ziyi as his rival and friend Gong Er, the heavily stylised picture is a story of honour, principle, betrayal and forbidden love all set in a time of turmoil.
Wong, also president of the jury at the cinema showcase this year, said he was determined to get beneath the surface of martial arts in a way most films in the genre had not.
"'Grandmaster' is a film about kung fu. It tells you more than the skill," he told reporters after a press screening and ahead of the opening night gala.
"It tells you more about these people, martial artists, the world of martial arts. What is their code of honour? What is their value? What is their philosophy?
"I hope this film can bring the audience a new perspective about martial arts, kung fu and also Chinese," he added, wearing his trademark dark glasses and speaking in English.
The idea for "The Grandmaster" was first announced more than a decade ago and it took the notoriously slow filmmaker four years to make, involving rigorous training for both Leung and Zhang which both actors said changed them profoundly.
Leung's character, which dominates the first part of the film, is based on a real-life master of the same name who developed the Wing Chun school of martial arts and counted Bruce Lee among his students.
Gong Er's character gradually takes a central role, and her repressed longing for Ip Man brings to the fore Wong's mastery of melancholy, which he showed so memorably in his best known film to date "In the Mood for Love" also starring Leung.
IRANIAN FILM DEFIES BAN
Leung, 50, said he started training for the part four years ago, and reportedly broke his arm early in the process.
"There is a spiritual side of kung fu and that side cannot be learned from books or by fact-finding," he said. "It grows spontaneously. So that's why I had to practise four years. You can only achieve that thing through practice."
"The Grandmaster" marks the official start of 11 days of screenings, photocalls, interviews and parties across Berlin where hundreds of movies will be screened, reviewed and traded at a film market that accompanies the Berlinale.
Matt Damon, Anne Hathaway and Nicolas Cage are expected on the red carpet, as are European heavyweights Catherine Deneuve and Jude Law and Asian stars including Leung and Zhang.
In the main competition of 19 movies eligible for awards is "Promised Land", about the controversial drilling technique for extracting gas known as "fracking" and starring Matt Damon directed by his "Good Will Hunting" collaborator Gus Van Sant.
Steven Soderbergh's "Side Effects" is in part a critique of the pharmaceutical industry and boasts Law, Channing Tatum and Catherine Zeta-Jones in the cast.
Soderbergh, an Oscar winner for his 2000 narcotics drama "Traffic", has announced it will be his final big screen feature film, at least for the foreseeable future.
One of the most eagerly awaited pictures at the festival is "Closed Curtain", co-directed by acclaimed Iranian director Jafar Panahi who made it in defiance of a 20-year ban on film making imposed by authorities at home.
Out of competition is 3D prehistoric animation comedy "The Croods", featuring the voices of Cage and Ryan Reynolds, and "Dark Blood", which River Phoenix was filming when he died aged 23 in 1993. (Reporting by Mike Collett-White, editing by Paul Casciato)