Photos: Motorcycle concepts from Tokyo

As a large part of cornering on a motorcycle involves leaning over, a four-wheeled motorcycle would seem impossible. But Yamaha seems to have gotten a handle on this idea with the Tesseract concept, which uses a double scythe suspension that lets the twin motorcycle frames lean to either side.

Yamaha designed the Tesseract with a hybrid power system, just in case you think a conventional motorcycle engine uses too much gas. The Tesseract would combine a V-twin gas engine with an electric motor.

For this sport-tourer concept, Honda uses a boxer-style six-cylinder engine, with a massive 1,800cc displacement.

Although the cowling looks sharp and mean, the DN-01 is a rather moderate concept bike. Its seating position is almost upright, and it uses a reasonable 680cc V-twin engine.

Yamaha's Luxair concept enters Akira territory with tons of tech. Its hybrid powertrain uses an electric motor for extra boost and as a reverse gear. Yamaha equipped it with the Natural Sound Motorcycle Audio System, which can send audio to the rider's helmet via Bluetooth.

As the name implies, Suzuki designed the Biplane to capture the feeling of flying an airplane. The concept is sure to get plenty of lift from its 1,000cc V-4. Just hope you don't actually leave the ground.

Although Yamaha designed the MT-OS to look like a stunt bike, with a rear wheel made just for popping wheelies, the concept has some real tech. It uses an LED headlight and a keyless starting system.

Tech-wise, there isn't much to speak of with the Sakura. It uses standard running gear, such as a 1,000cc air-cooled V-twin. But it demonstrates a motorcycle design that looks like a work of art.

Yamaha explores a practical fuel-cell design for a scooter with the FC-Dii. Its fuel cell uses methanol to generate electricity, which can then be stored in its lithium-ion battery. That battery can also be taken out and recharged.

The FC-Dii uses a methanol-water mix for fuel and a 1 kilowatt fuel cell. Its tank holds 3.6 liters of its methanol-water fuel, but Yamaha hasn't released any performance figures yet.

The FC-Aqel is another fuel-cell concept scooter from Yamaha, but this one uses compressed, gaseous hydrogen, with two tanks mounted underneath the back of the seat.

The name of this concept stands for cute, clean, and compact. It uses an electric drive and is designed as a daily commuter.

Bobby is another electric scooter design, with a foldable frame making storage more convenient. You could ride this up to your office and store it in a corner for the day.