One of the traditions of retail in Japan is the New Year lucky bag, the slightly difficult to pronounce fukubukuro. A lot of fun for the consumer, retailers use the tradition to clear end of season inventory by offering a closed bag for a fixed price. Inside will be a mix of product that would have cost significantly more had each item been purchased individually. The catch is you don't know what you're getting; no peeking inside. The bags are often sorted into men's, women's and kids to make the decision lightly easier but what's inside is a simple game of chance.
Occasionally the luck of the draw can fall to the buyer; the bag at an electronics store may contain a computer instead of a hairdryer for example. But there are no guarantees and it is usually the early bird that wins the prize and stores that are known to provide surprise offers will have queues forming from the early hours of the morning. The offers continuing until the final bag is in the hands of the hopeful consumer and the shelves are nearly empty. And it's completely unrelated to the unfortunate Japanese "Sale" sign circulating to hilarity on Facebook.