The basis is a three-wheeled, 250cc trike, with a specially built toilet as the seat. It's important to note that the contraption does not run on the rider's (*ahem*) leavings. Rather, the vehicle runs on livestock waste, or waste water. The toilet-derived seat is just a rather blatant advertising device.
According to a Metro UK report, the bike "runs on biogas fuel (fertilized, purified and compressed livestock waste and household waste water) provided by the Shika-oi Town in Hokkaido and Kobe city."
This puts Toto at the front of the clean vehicle initiative in the Japanese market. The report says this vehicle could very well spawn a production model (we're guessing it wouldn't include the toilet seating), but there's no word yet on production timing or price for the poo-burning hog.