Panty fetishism
Panty fetishism is a fetish relating to underwear, particularly worn or soiled underwear. It can also involve printed or electronic material depicting exposure of underwear.
Pornographic magazines in the West have long contained advertisements for "used" women's underwear. However, this fetish has been carried to extremes in Japan.
Buru sera is a Japanese (Engrish) term for "bloomer sailor" -- a reference to the underwear of teenage schoolgirls in "sailor"-like uniforms. This fetish is popular in Japan where female adolescence is perhaps more prominently revered as the idealized form of beauty than it is even in Western cultures.
The term refers to the sale and exchange of the panties of these schoolgirls, as independent transactions between female and adult store and the store and the buyer. Girls who participate in this business will exchange their panties at adult stores on their way to school, and returning them soiled for profit. The more soiled they are, the more they will fetch at sale. Further increasing the value is attaching girls picture or bio to the panties, personalizing them for the consumer. At one point, such panties were even made for sale in vending machines in the Chiba Prefecture, until they were found to be illegal under "antiques-resale" legislation.
