At the beginning of this year, Mercedes showed off the F 015, a shining hunk of metal that represents the automaker's vision for the future of luxurious, electric, autonomous driving. The "Vision Tokyo: Connected Lounge" extends that idea. Aimed at millenials instead of executives, it's a "a chill-out zone in the midst of megacity traffic mayhem."

Electric driving isn't all about batteries. Toyota—along with Honda and a few others—believe that fuel cells are the clean way to power the future of cars. To highlight the upside of the new technology, Toyota created the FCV Plus. The concept works as a car, but also as a mobile power generator.

For its Tokyo showing, Mazda reached into the past to think about the future. The RX-Vision concept car is powered by a concept powertrain, the Skyactive-R rotary engine. Rotary engines create power by spinning rotors, rather than pumping pistons, and Mazda successfully used the setup in 1991 to win the 24 Hours of Le Mans.

Suzuki may have pulled out of the US market in 2012 but it's still going strong in Asia, and is already thinking about its 100-year anniversary in 2020. Its "Mighty Deck" concept is a sort of utilitarian minicar, with a canvas top and small pickup bed to haul your fun-havin' gear.

Nissan has pledged to put autonomous cars on the road by 2020, and it created the IDS to imagine what form that might like. The concept mimics the driver's style when it's driving itself around, an idea we've seen from other automakers, and one that seems to defeat the entire purpose of handing control over to machines that are better at this than we are. Also: It'll give you restaurant recommendations.

Nissan's got ideas beyond self-driving cars. The Gripz concept is a funky crossover with a "dual personality"---drivers can use it to get around town, or treat it like a dune buggy on an off-road adventure. It runs on the motor used by the electric Leaf, paired with "an efficient petrol engine." We'd say there's no way Nissan would make something that looks like this, but hey, these folks make the Juke.

Even Yamaha got into the concept car festivities in Tokyo. The motorcycle manufacturer drew up the 4Wheeler, a lightweight, mid-engine, two seat sports car. Not a bad effort from folks used to working with two wheels.

Nissan also showed off the creatively named "Teatro for Dayz," an ugly, boxy thing. The concept's based on the notion that today's younguns don't care about driving, they care about sharing online experiences, so it's packed with LED screens. What, no holograms?

Another Toyota concept that made its premiere in Tokyo, the Kikai is decidedly steampunk, and an homage to the idea that cars are the work of craftsman. That's why all the machinery is so obvious—it should be admired, Toyota says, not hidden. Just don't expect the same idea to have an impact on any of the automaker's econoboxes.