Plenty of other people ordered them, but Toyota knows what good PR is.
All the way back in 1963, Chrysler made an experimental turbine car, giving them to select people to test them out. One of these was the President of Mexico, who ran his on tequila. It was great publicity, and now Toyota is cashing in on something very similar by delivering the first unit of the world's first mass market hydrogen fuel cell vehicle, the Mirai, to the prime minister of Japan. Delivery of the car to Shinzo Abe was obviously a very well publicized event.
Toyota seems to think that this move will also help with infrastructure implementation, and that seems pretty logical to us as well.