Subscribed. Though I'm surprised they're not starving by the end of chapter 3. And "what do you want to eat?" -> but you have no money.
I was talking to my friend about this manga today and apparently it's actually somewhat common in Japan for people to have unused homes in rural areas, with the aging population and urbanization. You inherit the property but can't uproot your life to properly use it.
I've also heard that property often depreciates in value in Japan.
I mean, it's mostly the same thing as everywhere else. Old buildings are more run down and less attractive than new ones. Land values go up and down based on demand; demand in Japan's countryside is particularly going down, but the US has lots of ghost towns too, plus semi-evacuated inner cities.
The one distinctive thing is a strong bias against used houses, so those depreciate particularly quickly in resale value. (Flip side, that might mean you can get nice deals if you have a Western attitude -- though perhaps such houses aren't built to last.) Of course if you're anywhere near a big city, the land is probably most of the cost of the house+land package.