The Dreamcast is often described as a system that was ahead of it's time, and in many ways it was. You only have to look at all of the ingenious peripherals and add-ons; even the lowly memory card, the VMU, is a technical marvel when you think about it. The entire range of official and unofficial enhancements is as staggeringly large as it is diverse, but perhaps the most important of them all is the one many of us forget is even there these days - the little modem stuck to the rear of the system. While the modem and the internet services it allowed played something of a minor role in PAL territories, and online gaming was a huge success in the US, over in Japan the humble modem played a much more interesting part in the story of the Dreamcast.
While the Dreamcast is first and foremost an entertainment machine, the modem allowed Sega Japan to look beyond it's primary function and decide that the console should also be used for other, non-gaming purposes. For instance, the console was installed in Toyota car showrooms and a whole range of bespoke 'Doricatch Series' GDs were produced. These were little more than advertising demos for various Toyota vehicle models and are today some of the rarest examples of NTSC-J exclusive Dreamcast software on the planet.