Overview: 15 million people commute in and out of Tokyo every day, and most of them now use prepaid e-money cards. Because one card can be recognized by multiple transport companies, the system has streamlined automated fare collection. A card's IC chip has an e-wallet function, and can store information such as boarding section and expiration dates on monthly passes; all of which can be verified in just 0.2 seconds. See how these cards and the technology behind them have transformed rail travel in Japan.