That must be the public transport. The two largest cities provide a grid of subway and regular trains, capable getting you nearly everywhere withing a reasonable amount of time, and for a reasonable price.
Aside of the standard train tickets, the Japanese also managed to put in some special discount tickets, like a Day Pass. In Osaka, the Day Pass costs 1000 yen, which will pay off after 5 of the shortest rides the system has to offer. Great thing to have when you're out shopping and you have to go up and down to various regions of the city.
But it gets better.
On Fridays, the Osaka Subway has a No-My-Car Day Pass, which is 400 yen cheaper than the regular Day Pass, and is meant to encourage people to take the sub instead of their car.
Here is the kicker; the vending machine warns you about the NMC-pass:
Now, if you're stupid enough to touch the pad for the regular Day Pass, you get this:
Brilliant.
Cheers, K.