The country's king of elderly porn, Shigeo Tokuda, 74, might look like an average Japanese grandfather but appearances can be deceiving. Porn is a fast growing niche market in this greying society.
A former travel agent who quit his job just four years ago, Tokuda has stretched the limits of eroticism among the silver-haired, overturning social norms in a country where people are expected to grow old gracefully.
Although he hardly stands out in a crowd at 160 centimeters (5 foot 3 inches) and carries a paunch, Tokuda's 15-year X-rated acting career and his appearances in more than 300 hardcore sex movies have silenced his detractors.
"I've always wanted to do something different, things people don't normally do," he said one recent afternoon in his small office, wearing a nondescript sweater and looking like the "salaryman" he once was.
Since his top rival died recently at the age of 90, Tokuda has become the country's undisputed king of Japanese "mature porn" a category that has flourished in the fast-aging society since it emerged a decade ago.
His latest series of no-holds-barred blue movies, dubbed the "Tokuda Project," includes such titles as "Forbidden Elderly Care" and is advertised with slogans like "Oh, What Pleasure... Don't be Ashamed of Getting Old!" and "Lust is Medicine".
The oldest porn actress Tokuda co-stars with is 72-year-old Fujiko Ito, featured in some of the titles frolicking in hot springs with Tokuda or on traditional tatamis, wearing a kimono.
But the "master of erotica," as Tokuda is often billed in the videos, also appears with actresses who are more than five decades younger.
"Sometimes it takes a while to start the action, but (Tokuda) is rich with the experience we make use of, and so in that sense it is very easy to shoot," said his director Gaiichi Kohno, himself an actor and head of production company G's Spot Co.
In a country where close to 30 million people are aged 65 or older and the birth rate is low, Japanese pornography producers have unearthed a lucrative market. Insiders say sales in the genre have doubled in the past 10 years.
Sex movies now rake in about 20 billion dollars a year in Japan, and elderly porn accounts for between 20 and 30 percent of the market.
"I expect this category to grow further," said Ryuichi Kadowaki, president of Ruby, a company outside of Tokyo that specializes in mature pornography and distributes Tokuda's movies.
Mature pornography has also grown as male viewers are comforted by the thought of being attractive to women, even if they are older, Kohno said.
The company is now seeking to export the brand, especially to the United States and Western Europe.
"Elderly people have a lot of time on their hands, and I think that their boundaries of possibility are widening in various ways," Tokuda told AFP. "In that sense I want to give them vitality."
Off screen, Tokuda hardly resembles the erotic expert he plays on camera, where he deftly shuttles from the bedroom to playing a doting father and a stiff-lipped gentleman wearing a tailored suit and holding a pocket watch.
Tokuda, which is his stage name, is happily married in real life, with two children and a grandson. His hobbies include photography, hiking and singing traditional Japanese songs with a lute to accompany dancing geishas.
Despite his long acting career, Tokuda said he has managed to hide his second life from his family.
He said his wife of 45 years suspects he plays a minor role in pornographic movies but has not brought up the subject with him.
"My daughter, however, got a whiff of what's going on after she peeked into my script," he said. "She asked me: 'So until when do you think you're going to continue this?' I killed the issue by remaining silent."
Despite his apparent sex god status, he said, he is rarely stopped in the street.
"Once, while I was a still a salaryman, I was stared at twice by the same person while I was waiting for the train," Tokuda said. "But I think he would have been too embarrassed to approach me anyway."
The septuagenarian said that, to stay in shape, he walks everywhere and enjoys a healthy diet of eggs and vegetables. His dislikes include eating fish "because it's too bothersome to pick out the bones".
He once dabbled with Viagra several years ago but having survived a heart attack has fore sworn stimulants.
"I can't really say clearly what lies ahead, but I think I can still go five more years, until I am around 80," he said, laughing as his shiny head turned a rosy shade.