Dragonball fans can expect an older, fiercer version of hero Goku in the Hollywood adaptation of the famed Japanese cartoon series about two magic-wielding rivals who compete for seven orange spheres that will grant the holder a perfect wish.

The filmmakers behind "Dragonball Evolution" added 10 years to its hero to give the movie a grittier look, actor James Marsters said at a press conference Wednesday.

In the comic book series, "Goku is seven years old and fighting midgets all the time," said Marsters, who plays Goku's rival, Lord Piccolo. "We muscled it up."

Justin Chatwin, the 26-year-old Canadian actor who plays the teenage Goku in the movie, said the cast learned several different martial arts styles for the movie. He initially was worried about taking the role because of his slender physique.

"I was looking in the mirror, going like, 'I'm a beanpole, how can I pull off this role?"' said Chatwin, best known for playing Tom Cruise's son Robbie in "War of the Worlds" and a teenager stuck in limbo after an attack in David Goyer's "The Invisible."

But while Goku was given a more adult interpretation, director James Wong said he toned down another key character - Roshi, a flirtatious, Hawaii-shirt wearing martial arts master - to appeal to a broader audience.

Roshi, played by veteran Hong Kong actor Chow Yun-fat, is "a little tamer than he is in the manga," Wong said.

Wong said condensing the dozens of "Dragonball" manga books that have already been published was a tough task.

"All that we hoped to do was to preserve the essence of Dragonball - the fun, the thrills the adventure," he said.

"Dragonball Evolution" will be released in Asia in March and in the U.S. on April 8.