According to the Japanese Vending Machine Association there are over 5.6 million vending machines in Japan. That's around 1 for every 23 people. This estimate doesn't include things like train ticket machines and gacha. If these were included the number would be much higher.
Remarkably ReliableJapanese vending machines (jidohanbaiki ~ 自動販売機) made their first appearance in late 19th century. Many vending machines in the country are showing their age. Whatever their age, they rarely malfunction. They're always in working order and almost always fully stocked.
Why So Many?Japan has the highest number of vending machines per capita in the world. There are several reasons. Japan is a safe country — vending machines aren't vandalized (even in remote locations). In the rare cases that graffiti can be found on machines — it almost looks like permission was obtained.
Japan is highly urbanized and its currency is suited to vending (100 yen and 500 yen coins and machine verifiable bills). People in Japan think nothing of putting a 10,000 yen bill ($125 USD) into a machine.
Another reason for the success of vending machines in Japan — Japanese people walk a great deal. Pedestrian traffic is highly centralized (around train stations).
Products and PricesThe vast majority of machines serve beverages. The most popular beverages are unsweetened teas with no artificial ingredients. However, it's possible to buy virtually anything from a vending machine in Japan.
Vending machine prices are amazingly standardized across the country. A 500 ml beverage usually costs 150 yen. Machines in prime locations rarely have higher prices. There are a few exceptions such as certain ski resorts and the machine at the top of Mount Fuji.
Machines in offbeat locations are sometimes discounted.
Man Versus MachineVending machines are used to augment human labor. For example, many cheap eateries have them. You pay for your items in a machine and hand tickets to human staff.
Japanese companies views robots (such as vending machines) as an important part of the solution to Japan's aging society. Aging workers can be replaced with industrial robots and process automation.
Modern MachinesModern vending machines accept electronic payments from smartphones and train cards. They can also validate your age (a system called TASPO) for certain restricted purchases.
Privacy and MannersIn Japan people highly value their privacy. Vending machines sell anything that people are shy about buying in a shop.
Traditionally, it's rude to walk and drink a beverage at the same time. Some Japanese vending machines still have rain covers so that you can stand and drink your beverage beside the machine. It's still possible to see people doing this in Japan today. Younger generations of Japanese walk and drink.
Machine NostalgiaVending machines are so engrained in Japanese culture and lifestyle that people are nostalgic about them.