The FT-Bh - Future Toyota B-segment hybrid - promises an emissions rating around half that of the average city car.
Toyota plans to do this through various advanced technologies, such as using extremely lightweight materials in its construction that will help keep the concept's weight under 800kg.
The FT-Bh will showcase an aerodynamic body, with flowing panel lines and wind-sheering fins at the rear - as seen in the first teaser shot.
Specific details on the FT-Bh's powertrain are unknown at this stage, however, power will come from a small hybrid system, offering typical power specifications of a city car.
Other highlights include LED lighting, including taillights that run along the edge of the rear fins, and unique headlights. Toyota also says the concept will preview "thermal energy management" and "electricity saving" technologies.