CHOFU, Japan » Daisuke Terai plays one of the best-known characters in the history of science fiction, but few fans have ever seen the actor’s face. That is because Terai dons a bright silver and red rubber suit before stepping onto a set made of miniature trees and buildings to do battle as the cosmic superhero Ultraman.

On a recent afternoon, Terai’s character was locked in mortal combat to defend the Earth from a giant extraterrestrial dinosaur with glowing eyes and forked spikes called Grand King. When the cameras paused, a sweating Terai, 36, peeled off the top of his Ultraman suit, while stagehands removed Grand King’s foam spikes to reveal a zipper down the back of the 65-pound costume.

For decades, Japanese studios dazzled, terrified and tickled global audiences with monster movies and television shows featuring actors in rubber suits laying waste to scaled-down Tokyos, or dueling atop miniaturized Mount Fujis. The genre, known here as "tokusatsu," or "special filming," helped take the Japanese film industry global by creating such fabled creatures as Godzilla and Mothra, pioneering the way for other fantasy genres like animi.

But now, in an era when lifelike digital effects have made the use of small models and suited actors look quaint and kitschy, tokusatsu is rapidly becoming a thing of the past. The last Godzilla movie shot in this style, the aptly named "Godzilla Final Wars," was released almost a decade ago, after a half-century span during which the creature appeared in 28 films, sometimes every year.

Only two companies still use tokusatsu effects: Tsuburaya Productions, maker of Ultraman, and Toei, which produces "Kamen Rider" and "Super Sentai" (known in the United States as Power Rangers). All are low-budget television series for children that feature oversize superheroes. Tsuburaya also makes movies, with its newest film, "Ultraman Ginga," to be released this month in Japan.

Now, when Hollywood makes tokusatsu-inspired films – like this summer’s "Pacific Rim," with its giant robots, or an upcoming Godzilla movie – it relies on flashy computer graphics.

"One day, we looked around and realized that almost no one is making tokusatsu anymore," said Shinji Higuchi, one of a handful of Japanese directors who still have experience in the genre, having directed three movies in the 1990s featuring the giant fire-breathing turtle Gamera. "We don’t want this technique to just quietly disappear without at least recognizing how indebted we are to it."

In response, Higuchi is trying to, if not revive tokusatsu, at least chronicle it for younger generations. Last year, he helped organize the Tokusatsu Special Effects Museum, a traveling exhibition that presents the history of tokusatsu, going back to its origins in World War II-era propaganda films with flying model airplanes so realistic that American intelligence officers thought the films were actual combat footage.

The man who shot that footage, Eiji Tsuburaya, went on to create the original Godzilla in the 1954 black-and-white movie that became a worldwide hit and started the tokusatsu genre. The exhibition, which is doing a circuit of art museums in Japan, displays the movie camera of Tsuburaya, who also created Ultraman, as well as props including an enormous Godzilla foot, used to crush tiny buildings, and models of fanciful spaceships, submarines and ray guns used in dozens of superhero and monster movies.

"We had to improvise, and make it all look real on screen," said Haruo Nakajima, the actor who played Godzilla in the original movie and in dozens of subsequent Godzilla films.

Now 84, he recalled how the creator of Godzilla, Tsuburaya, who died in 1970, had to scramble to find enough rubber, latex and cotton to make the costume during the shortages after the war. "You don’t learn this from a textbook," he said, "but by doing. There is no chance to learn now."

The central government’s Agency for Cultural Affairs helped pull together the exhibition by gathering the props and models from retired stagehands or studio closets. Tomonori Saiki, who heads research on movies at the agency, says that Japan has only belatedly come to appreciate the cultural significance of tokusatsu, which he calls a product of an era after defeat in the war, when a still-recovering Japan drew from its traditions of craftsmanship and working in miniature, seen in pot-size bonsai trees, to compete with bigger-budget American films.

"Our hope is that the exhibition will help younger generations find inspiration to take tokusatsu in a new direction," Higuchi, 47, said.

Here on the set of Ultraman Ginga, the newest television variant of the half-century old hero, most workers were veterans in their 50s and 60s, who arranged tree branches on the set to look like a miniature forest, or placed firecracker-size explosives in Grand King’s foam costume to explode when shot by Ultraman.

The director, Yuichi Abe, said this use of real actors, models and even explosives gave tokusatsu a level of realism that is not possible with computer graphics, or CG.

"CG can only do what the programmer tells them to do, so there are no surprises," said Abe, 49, who has directed a half-dozen Ultraman movies and television series. "With tokusatsu, every take is different. You never know how it will turn out, just like in the real world."

Still, Abe said he was also relying increasingly on computer effects, mixing them with tokusatsu scenes. One example was flying aircraft, which had previously been miniature models, but were now entirely digital.

One scene, in which Grand King hurls a gigantic robotic companion named Jan Nine into Ultraman, required putting a large gym mat behind the actors, just out of the camera’s view. As filming was about to begin, Terai, the actor, donned his silver face mask and struck a dramatic martial arts pose. Stage hands flicked a small switch on his costume to turn on a light on his chest.

"Ready!" yelled Abe, giving instructions in a mix of Japanese and English. "Start!"

On cue, the actor playing Jan Nine leapt into Terai, knocking both onto the gym mat.

"Cut!"

"This is one effect that you don’t get from CG," said Terai afterward, rubbing his shoulder. "Real pain."

Terai, who has played Ultraman for 16 years and watched the show as a child, said there was one other benefit from having a real actor: the ability to shake hands with his young fans.

"Children know a CG is fake," he said. "They want a human Ultraman."

But the lack of young workers on the set, besides the actors, points to a worrisome trend, said Abe and others. As they retire, there will be no one who has learned the skills of making the sets, miniature models and costumes to take their place.

Shinichi Oka, the president of Tsuburaya Productions, the company that Tsuburaya founded, said the digital revolution had made change inevitable, though use of models and miniatures would continue in a limited role. The biggest reason was a new generation of audiences, who have come to expect the dazzling digital effects of Hollywood.

"Sure, I would love to keep making tokusatsu, but the reality is that CG is now cheaper, faster and can do more," said Oka, who worked as cameraman and then director on nine Ultraman movies. "If Eiji Tsuburaya were still alive, he would use CG. We have no choice."