Next time you spot a short, bespectacled old man closely examining a woman's curves as she climbs the station stairs, don't jump to conclusions. Instead of a would-be groper or pervert, that man could be Makoto Kakeda -- one of Japan's most respected mannequin sculptors.

For Kakeda, a 70-year-old designer at Tokyo-based Tomane Co., watching women is part of his job. And it is those keen observations that have helped him create more than 300 clay mannequin prototypes during his 47-year career -- prototypes whose polyester clones have graced show windows at such top fashion shops as Chanel and Yves Saint Laurent.

Amazingly enough, Kakeda has accomplished this without a hint of fetishism or obsession with sex. In fact, he is dead serious about -- and committed to -- his work.

"Every mannequin I sculpt, I work at it with all my might," Kakeda said in a recent interview at a quiet Tokyo cafe. "Every time, it's been such a dramatic battle. Even now, at my age, I stay up all night sometimes, working on my creations."

A graduate of an arts college in Kyoto, Kakeda entered the trade in 1957 for a reason shared by many other mannequin artists: It was the only way he could find to combine art with making a living. But it wasn't an easy switch.

However, a year's apprenticeship in Spain from 1964 exposed him to the global fashion business and, convinced that Japan would soon have a full-blown mannequin industry, he decided to focus on creating them. Ever since, he has maintained that mannequins are the ultimate form of popular art.

"You would feel empty if you felt your product was just a decoration and not deeply connected to human existence," he wrote in his 2002 book, "Manekin -- Utsukushii Jintaino Monogatari (Mannequins -- A Story of Beautiful Human Bodies)."

"That feeling gives me the energy to keep creating something new, to keep feeling the times."

To keep up with the times, following approaches from other companies Kakeda swapped firms three times (rare for someone of his generation), sometimes combining management with his hands-on work. At Tomane, where he's now left management behind, his co-workers compare his attitude to that of Pablo Picasso.

"He is a man who has stubbornly stuck to making mannequins, just like Picasso, who worked right until he died," said Jun Sakita, a 39-year-old fellow sculptor at Tomane. "He is among the very few who can live like that."

During a recent visit to the basement studio, where bare body parts were strewn on the floor, Kakeda was working on a four-body series that Tomane aims to market for next year's fall season. The mannequins, modeled on working women age 30-35, are meant to complement the type of clothes that are now all the rage -- including bikyaku (beautiful legs) trousers that appear to lift women's hips and make their legs look longer.

The studio, a large, open concrete space, is also the scene of passionate debates on female body forms between Kakeda and four other designers. The bottom of a 90-year-old competitive swimmer was the recent object of some serious musing. Kakeda's younger co-workers were amazed that he could find sex appeal in so unlikely a posterior. They all agree, though, that his female works outshine his male ones -- which is perhaps not surprising, as he freely admits to preferring his work on the fairer sex.

Kakeda said above all it is the faces that he loves. It's what separates good mannequins from the others, he believes, so he often spends days working on minute facial details -- sometimes taking a head home with him to work on there.

Though mannequin designers may be professional students of human body forms, the business of re-creating what they see -- which is even today almost all done by hand -- is not in such great shape.

In the 1960s, mannequins were almost the only display vehicles for clothes. Today, many boutiques dispense with them, instead showing their clothes spread out on tables. And in times of recession, headless torsos are favored as they take up less space. According to the industry group Japan Mannequin Display Association, the number of full-body female mannequins produced per year fell from 94,731 in 1976 to 10,625 in 2003.

The drop in production, however, doesn't faze Kakeda. "We simply had too many in the past," he says.

Utlimately his career choice is more about pleasure than business: "What's fun about the whole process is re-creating not just a model's body but her attractiveness. So it's all up to me to feel something from her."