The Subaru WRX is without a doubt a strong candidate for the car model with the highest number grades and special editions. Add to the many existing WRX variants a new one that has just launched in Japan. It’s called the WRX S4 STI Sport, and it debuts as the range-topping WRX S4 model.

It’s not the first Subaru vehicle to get the STI Sport designation in Japan: both the Levorg and BRZ have got there first. As with those models, the WRX S4 STI Sport is jointly developed with Subaru Tecnica International (STI), and that’s obviously a good thing.

Subaru claims the new model brings improved driving performance, combining supple ride comfort with agile handling and increased cornering stability. That’s due to mechanical upgrades such as the STI-tuned Bilstein DTMatic II inverted struts at the front, as well as the conventional dampers and springs at the rear (also tuned by STI).

The WRX S4 STI Sport also features unique exterior design touches, headlined by the dark metal front grille with STI badge and dark gray 18-inch alloys. A number of black-painted elements are easy to spot and they include the boot lid spoiler, shark fin antenna, mirror caps, and front fender trim.

Inside, the range-topping WRX S4 gains Recaro front seats upholstered in Bordeaux leather and ultra suede, leather-wrapped steering wheel with red stitching, stainless steel sill plates, and the STI logo visible all over the place.

The engine is the same as in the regular WRX S4: 2.0-liter four-cylinder Boxer unit rated at 300 PS (296 hp) and 400 Nm (295 lb-ft) of torque, mated to a Sport Lineartronic CVT automatic and Subaru’s AWD system.

The Subaru WRX S4 STI Sport will arrive in Japanese dealerships on September 21 with a starting price of 4,093,200 yen (roughly $38,850), including the local consumption tax.