The behind-the-scenes tales of hit products and creations from Japan: this is Japan's Top Inventions. On this episode, we discover conveyor belt sushi, an invention that's trundled its way to countries and regions around the world. The technology, in which plates of sushi are delivered via a rotating conveyor belt, actually traces its origins to a single eureka moment in a beer factory in 1950's Japan. This time, the inside story of the one man who brought this Top Invention to life.