I don't know about "notoriously difficult to live as a foreigner in Japan." I mean, you DO need a visa (residence status), but it's easier to get than a lot of countries.

You don't legally need to even be a resident to buy a property here, so there's that.

And yes, beautiful homes in beautiful places can be found for quite cheap here. But what social media doesn't tell you is that most of those places need a lot of work, are very far away from anything, and there is no "growth" of any kind in those areas. If you have the cash, no kids, work remotely and are willing to learn the language/culture... totally doable.

Buying is easy. Renting is hard. You can go buy ten houses on a tourist VISA. Just find a property agent.