There are more vending machines in Japan than in the entire rest of the world put together.
Why is this, you ask? Is it because the Japanese are genetically predisposed to an elevated level of thirst?

Nope. It is because the owners can be pretty sure their machines are not going to be vandalized, robbed, or otherwise tampered with.

Theft is just not much of an issue in Japan. I see many parked bicycles that aren't locked up, and so far my umbrella has always been there when I come back out of a store, despite it being the stylish plastic kind that you can only get at an AM/PM Mini Market.