The car garages. I never drove a car in Japan, but it looked like there was a system and some kind of futuristic hydraulic automation thingy to put your car in an available slot??
But in general, I got a lot of retrofuturism vibes in Japan.
Also, while not technology, it is worth mentioning that people there are incredibly polite and friendly - even in Tokyo rush hour.
They have this in Denmark if I understand correctly. Like you park in on of the robot lifts, there was 5 where I was, then the machine parks your car, and when you’re done it collects it back.
I wouldn’t say they are common but they definitely exist. The new harbour front parking in Aarhus is fully automated; you drive under the public library, which is raised on concrete pillars, and enter into any available “garage” - after you’re out of the car, you press a button to close the “garage” and the floor plate is lowered down for automated storage. An empty plate is then brought back up and the garage is opened again for the next person. It apparently increased capacity 40% to do it this way.