For hundreds of years the Japanese have enjoyed nightly baths. Now, younger Japanese have added a new ritual, the morning shampoo, and their elders are wondering if all this cleanliness doesn't add up to overindulgence.

The daily morning shampoo, known as "asa shan," has become a symbol of youthful excess in Japan - excess chemical use, excess energy use, excessive narcissism.It highlights a gap between the generation that toiled to rebuild the country from the ashes of World War II and its offspring, which has known nothing but affluence.

At best, analysts say, the trend toward fastidiousness is a harmless fad, fueled by manufacturers trying to expand stale markets for personal cleaning products.

At worst, "Asa Shan Will Destroy The Country," screamed the title of a recent article by Hiroshi Inamura, a Tsukuba University professor of public health.

Cultural anthropologist Masao Kunihiro said, "Excessive preoccupation with one's bodily cleanliness appears to be bordering on a kind of disease."

In the past, daily shampoos were rare because of the lack of electric hair driers, the difficulty of heating baths with wood or coal, and the custom of all members of a family sharing the same bath water.