For the past several weeks some good Samaritans have been sending gifts to various child-welfare facilities throughout Japan. All of the senders identified themselves as “Naoto Date,” the name of the fictional character who was a professional wrestler called Tiger Mask in a popular animated series that aired between 1969 and 1971. Date also grew up in a child welfare facility, which for all intents and purposes is an orphanage; when he grew up and made money, he gave some of it to the facility that raised him.

In at least three of these charitable incidents, the anonymous donor deposited gift-wrapped randoseru at the entrances of the facilities. English-language news outlets translate this word as “school bags,” which doesn’t do justice to the thing it describes. Randoseru, a local rendering of the Dutch word ransel, is considered a uniquely Japanese accoutrement to the lives of young children. Randoseru are those boxy, hard leather backpacks that elementary children wear on their way to and from school and which are considered mandatory for no other reason than that everyone at that age wears them. Traditionally, they are expensive, which explains why the anonymous gift-giver chose that particular gift: orphanages, he figures, probably wouldn’t be able to afford them. He obviously thought he was giving those kids, who likely attend public schools alongside non-orphans, a measure of self-esteem.

Legend has it that the randoseru craze was sparked when the future Emperor Taisho was given a genuine Dutch backpack as a child, and while explanations for the subsequent popularity of such an accessory focus on practicality, a closer look at the phenomenon reveals it has more to do with marketing and status. Because a child will only use it from the first to the sixth year of elementary school (though many stop wearing theirs by the beginning of fifth year because randoseru look ridiculous on larger kids), he or she will most likely only possess one, and so the randoseru represents in commodity form a child’s formal entrance into the educational system. It is an emblem of a rite of passage. All children show up to class on the first day of first grade dressed in their school uniforms and sporting identical and — most important — brand new randoseru. God help the child who shows up with his older brother’s or sister’s hand-me-down bag or even a standard canvas backpack, no matter how new and fashionable. The kid would be teased mercilessly.

Consequently, manufacturers of randoseru have always been assured of a stable market unaffected by fashion, and have brokered deals with private schools, some of which require that their students buy only the randoseru they provide as part of the school uniform. But, as everyone knows, the number of births is dwindling in Japan, which means fewer little backs for makers to furnish, and so there is suddenly heated competition among these companies for a diminishing pool of customers. Last year, the huge retailer Aeon came out with a new “A4” randoseru that was slightly wider so as to accommodate A4-size documents, which previously had to be folded to fit in a classic randoseru. Aeon also offers a wider variety of colors. Traditionally, boys wore black and girls red, but Aeon has a line of 21 colors. All manufacturers have followed suit, including the most prestigious randoseru maker Tenshi no Hane, which saturates the airwaves with commercials all year round and not just during back-to-school season; and Kyowa, which introduced some years ago a new kind of acrylic called clarino that doesn’t crack the way real leather does over time and, more importantly, is lighter than leather. Though authenticity has something to do with the prestige factor of randoseru — and 20 years ago a kid who showed up to school with a vinyl one was automatically outed as a plebe — clarino, made by the chemical company Kuraray, has become the standard material for high-end school bags.

By high-end we mean a top price of ¥52,000. Aeon’s prices are a bit more reasonable, starting at ¥29,000, but the only company that has boldly bucked the trend is the discount home furnishings retailer Nitori, which partnered with another chemical company, Toray, to manufacture exclusive randoseru for Nitori’s stores that sell for either ¥9,900 or ¥19,900. If you can get the grandparents to buy a desk with that, they’ll knock off an extra thousand yen or two.

There isn’t much of a secondary market for randoseru except as mementos. Starting in the ’80s, young adults who started to feel nostalgic for their childhoods had their old randoseru refashioned into miniature versions that they displayed as objets d’art on their work desks or end tables. The Japanese Organization for International Cooperation in Family Planning collects old randoseru, which they then distribute to schoolchildren in places like Afghanistan, where the prestige and fetishist elements have no meaning and where they really are accepted gratefully as practical accessories. In fact, some of the other would-be Tiger Masks have not given randoseru to the orphanages they favored, opting instead for toys or even cash. We can assume that the persons who sent randoseru knew the exact number of children in the facilities they targeted. If they didn’t send enough it would defeat the purpose, since the whole point of the bag is that everyone has one.