I don't know if it actually Grab running Uber in Japan, I'd be surprised as they don't have an actual presence in Japan. But Uber is only Uber Black, and I would imagine that might just be the limo taxis of certain taxis companies that are behind.

The taxi industry is very regulated in Japan, so the Uber, Grab, Lyft, etc. business model is basically not allowed.. And I would imagine the number of private people with a car wanting to drive strangers is pretty low. But let's not turn this thread in to an ride sharing technicality thread.

Suffice to say, the Uber App will book a car to go between the airports it will set the rider back 28K+ yen.