Even after seven years here, there are new things to learn. Yesterday I sent cash in the mail using the post office’s registered cash envelope.

A genkin futo is a double envelope made of kraft paper; it costs 20 yen at the postal counter. You slip your cash into the inner envelope, which is attached to the outer envelope so robbers can’t exchange it for another one. For additional security, you seal the outer envelope and stamp your hanko (or sign your initials) along the seam of the seal.

The front of the envelope has a carbon form on it. You fill in the recipient’s address at the top, your address at the bottom and the middle part is used to note how much money is inside. The postal worker calculates the registration fee, stamps it up, gives you a section of the carbon form and your money is safely on its way.

As I went through the process, I saw three other people using genkin futo. As always, things become evident all around you once you know about them.