"I think that, as a subject, there is this something that only an older generation has and the young people do not possess. It is because they lived that much more. We should respect them and learn from them," quoth Japanese film director Gaichi Kono to Michiko Toyama of Time Magazine.

But what are his films about? Mortality and wisdom? The pathos of old age? No, silly. They're "elder porn", the latest trend in the Japanese skinflick business!

Old porn stars needn't retire when they can go thrusting on in films like Maniac Training Of Lolitas and Forbidden Elderly Care. Toyama also talks to a star of the genre, 74-year-old former salaryman who goes by the nom de porn of Shigeo Tokuda, and who hasn't told his wife about his secret double life. He's appeared in 350 films in 14 years, many with the popular theme of "old dad teaches sexy young daughter-in-law a thing or two". "Elderly people don't identify with school dramas," he says. "It's easier for them to relate to older-men-and-daughters-in-law series, so they tend to watch adult videos with older people in them."

Porn being porn, there's always been a corner of the market for silver sexers, but this is something bigger: one third of the vids available at Tsutaya, the country's biggest chain, feature 'mature women'. In a business where 'maturity' begins in your late twenties, in these reels there's no upper age limit: some of the actresses are heading towards their ninth decade.

One porn baron explained:

"Adult videos with young actresses sell well only in the first three months after the release. On the other hand, mature-women films enjoy a steady, long-term popularity, which after 10 years or so might lead to a best seller."

Let's hope they get royalties to supplement their pensions then. Um, go old Japanese ladies!