With the Japanese teenage girl underwear dispensing machines node, I feel it necessary to give some background information on this certainly "interesting" part of Japanese culture.
Most cultures of the world have a long held fascination with girls, and youth. In Western culture this tends to focus more on the sexual innocence and maturity, the Japanese seem to focus on the looks. This is not all expected as the culture of Japan has not exactly had a "equal-rights" view on women. An example of this fascination would be how a 20-something girl would be found very attractive in the West would look much too old in the eyes of many Japanese. Explaining why 30 year old women in Japan tend to carry teddy bears and act exceedingly immature. This interest in young, middle school or high school students gave rise to the fetish of "Bura-Sera." The word comes from the bloomers that Japanese schoolgirls use in P.E. (Buruma) and the sailor-like school uniforms (Sera).
This Bura-Sera fetish has given rise to the infamous "Panties Vending Machines" as well as small shops where young middle school and high school students drop off their old panties or take it off right on the spot for a few extra dollars. Although one might suspect that these are children from lower class families it is hardly the case. The truth of the matter is that, children from highly respectible families are a large majority of those that are doing this, and they think of it with a carefree attitude. To them it's just making a few extra bucks on the side, and some even go as far as prostitution. The attitude of these middle school kids appears to be, "It's fun, and if my parents don't know. What's wrong?"
Indeed it seems the population is only fuelng the demand. Underware is priced depending on its age and "stains," they carry an average price of about $20 USD although a photo of the underware's former owner can send the price skyrocketing. Even school uniforms are in high demand and some will pay big bucks to get some from certain schools.
In the end, one must ask themselves (Besides the obvious.) if this is making sex more a material matter than that of courtship and a lasting relationship.
Sources
http://www.snopes.com/sex/kinky/panties.htm
http://www.smn.co.jp/tks/key/burusera.html