Signs here are [obviously] written in Japanese and usually English too. It's these translated signs that are funny. More than 75% of the time, at least of the signs I've seen, they aren't correctly translated into English correctly. The translated signs are usually funny and are commonly known as "Engrish."
I went out with some friends a couple of weeks ago and this sign was posted beside a vending machine. It was funny to me at the time, so funny that I had one of them take my picture with it. Now that I look at it it's not nearly as entertaining as it was that night...after a few tanqueray and tonics!
2 months ago