RFID in Japanese Restaurants

Kaiten-sushi Restaurants are upping the technology ante in the land of the rising sun. People think of inventory tracking applications for the mighty RFID tags. Well, think sushi. In case you haven't tried Kaiten-sushi, it's basically sushi served on a conveyor belt around a sushi counter. The chef whips up the sushi on a plate, usually two to a plate, and the plate then travels on the conveyor belt, paraded in front of hungry diners until it gets picked up by a suitor. The magic is in the charging system. Historically, Kaiten-sushi restaurants have color coded the sushi plates to signify price category. For example, a cheap plate containing kappamaki might be blue, an expensive one containing o-toro might be pink. In the past, the server would have to count up the mountain of plates upon 'o-kanjo' (or 'bill please') and figure out the price. I was recently blown away by the Kaiten-sushi restaurant in the new Mori-built Roppongi Hills complex in Tokyo, where the waitress came by at the end of the meal and ran a device up the stack of plates. Beep beep beep. "Thank you sir, the total is 8000 yen." Wait...how did you...? Seeing my surprise and ignorance, she turned over one of the empty plates, and on the bottom was a small square shaped bump, barely visible under blue lacquer. It was an RFID chip implanted in the plate. Different chips for different prices. Cool. The tallying up of over 18 plates literally took less than 5 seconds. That, was an amazing experience.