The folks who make the decisions at Mazda's mothership in Japan have apparently green-lighted the next generation of rotary sports car, to be dubbed RX-9.

The news comes from Japan's Holiday Auto magazine, whose report says the car was inspired by the RX-Vision concept unveiled at last year's Tokyo motor show. The magazine's renderings show a car with tighter proportions that looks only remotely like the concept.

What the magazine doesn't cite are any credible sources, so take everything you read here with a grain of salt. We might see a prototype at the 2017 Tokyo show, a venue chosen to commemorate the 50th anniversary of the rotary engine, with a production model to be revealed in 2019 in time for a 2020 launch that would honour the Mazda brand's centenary. That would also coincide with Tokyo's hosting of the next Summer Olympic games.

The Skyactiv-R engine is rumoured to displace about 1.6L from twin 800-cc rotors and would generate something like 400 horsepower with the help of turbocharging. A target curb weight of "less than 1,300 kg" promises notable performance.

Other possibilities include the use of homogeneous charge compression ignition (HCCI), which would eliminate spark plugs and make the engine closer in concept to a diesel; this is believable enough given Mazda is already working on using that technology as one of its next steps toward further improving fuel economy. Mazda's main challenge will be engineering a rotary that complies with ever-tightening emissions requirements -- one of the reasons the rotary-powered RX-8 disappeared after 2011.

As with all recent Mazda rotary rumours, we'll believe this one when we see it.