Japan's oldest X-rated actress has thrown in the towel at 80 years old, partly because nobody could keep up with her.

Maori Tezuka is a former opera singer, but got into the "silver porn" industry at the fresh age of 71.

"Once the lights go on, you just do your best," she told local media.

"I have no regrets, but shooting became difficult when the actor wasn't my type," Ms Tezuka says.

Geronto-porn is a major market in Japan, and is said to account for a quarter of the content made in an industry which rakes in $20 billion (NZ$28.4 billion).

The industry started booming following the exploits of Japanese man Shigeo Tokuda, 82, who has appeared in films such as Forbidden Elderly Care.

Ms Tezuka has been asked to consider a reprisal in a couple of years; something she says she'll think about.

Newshub.