Kawasaki's best-selling motorcycle is not the lightning fast Ninja ZX-10R litre sports bike, the only Japanese bike still in the race for the World Superbike Championship. Nor is it the company's 200 mph ZX-14R Ninja projectile. Ironically, it's the diminutive Ninja 250 which translates the performance DNA of the brand into a more practical and affordable "learners" bike with definite sporting aspirations.