TOKYO - The stars and the director of "Spider-Man 3" gave no clear clues on Tuesday whether Sony's money-spinning superhero would return to the screen in a fourth adventure, but fans got a glimmer of hope from Kirsten Dunst.

Asked how her character -- Peter Parker's love interest, Mary Jane Watson -- had developed in the latest film, Dunst told a news conference: "I admire her bravery and she's always been a challenging character for me.

"I think this last film -- not the last film, but the third film -- has really been a culmination of that growth of family," she said, referring to the cast.

"It's really apparent on the screen because of all the hard work we've put into it," said Dunst, dressed in a black turtleneck and pleated knee-length skirt.

In a nod to the importance of the revenue-boosting international market, "Spider-Man 3" premiered in Tokyo on Monday. It will debut globally on May 4.

Sam Raimi were also at the packed news conference, but no reporters got a chance to ask the question on every fan's mind: will there be a fourth movie?

Entertainment Weekly magazine on Monday cited Raimi as confirming a long-held Hollywood rumor he might direct a movie version of J.R.R. Tolkien's "The Hobbit" if "Lord of the Rings" director Peter Jackson is not eventually hired.

Dunst separately told the magazine that a "Spider-Man 4" without Raimi, herself and Maguire would be "disrespectful to the whole team" and would be a big flop.

Japanese private movie commentator Jun Ishiko said the series, which has grossed a collective $1.6 billion so far, was far from losing its lustre, with the story's continuity and the actors' popularity huge draws for fans.

"There's friendship over many years, a triangular connection between people, lots of human things," he said in an interview.

The latest sequel's production, packed with stunning special effects, cost more than $250 million and represents a big financial gamble for Sony Corp (NYSE:SNE - news).'s Columbia Pictures.

Raimi said around 100 animators used new computer programs to portray the crumbling, morphing "Sandman," with staff spending much time and effort studying sand particles.

"When you get it under a microscope, it's actually made up of a million different things -- it's the most beautiful thing in the world, a grain of sand," he said.

Maguire, asked how both he and Peter Parker (a.k.a. Spider-Man) had matured in the third movie, said his character now dealt with conflict and tragedy differently.

"I was very excited in Spider-Man 3 because I feel like we really get into some new territory for Peter Parker," said the 31-year-old actor, wearing a light grey suit with shirt and tie.

"In terms of growing up, I'm six or seven years older now. Peter Parker is, like, six months older."