The behind-the-scenes tales of hit products and creations from Japan: this is Japan's Top Inventions. This time, personal information protection stamps: rubber stamps that make mail addresses unreadable. Just stamp, and a unique alphabetic pattern renders the underlying text illegible. These stamps were invented in 2007 to help protect personal information. We discover the story behind these stamps, now sold in over 20 countries and regions, and learn about the latest models.