Korea, too. Probably some other countries. I remember the PSP had an optional OTA antenna.

There have been several attempts at doing the same thing in the U.S., but none of them ever worked out for various reasons. Often it was because of the expense of upgrading the tens of thousands of TV transmitters across the country.

This one died in 2011: https://en.wikipedia.org/wiki/MediaFLO

In a small country with more centralized control of broadcasting and less territory to cover like Japan and Korea, it's much easier.