Japanese men are worrying about more than mere sweat as summer temperatures rise: talk of body odor caused by ageing is adding to anxiety in a land that prizes being squeaky clean.
Being Japan, it has also sparked a range of new products, from odor-eating suits to special chewing gum.
"My wife tells me that I stink," said company manager Atsushi Asami, 47, interviewed on a typically hot and humid Tokyo street. "I am concerned about ageing odor and know there are anti-ageing odor products, but have not bought them myself."
An on-line survey by CBIC Corp, a Tokyo-based company that sells deodorant products, found that 89 percent of 700 Japanese women in their 20s and 30s found men smelly in commuter trains.
Shiseido Research Centre, a laboratory affiliated with Japanse cosmetics maker Shiseido Co Ltd, sparked the trend to anti-odor products for older men when it discovered eight years ago a substance that it named "kareishu", or ageing odor.
The lab identified nonenal, a type of fatty acid, as the cause, saying unsaturated fatty acids and oxidative decomposition increase from around 40 years of age.
"Increasingly, people are becoming concerned about their body odor," said Tsuneaki Gomi, a plastic surgeon who runs a clinic on body odor in Tokyo.
"Japan is becoming more of a cleanliness and odorless society. And the name, kareishu, fits right in with that trend of the times," Gomi said.