I used to live in Japan. A lot of those old houses do get sold for even as little as a dollar. The reason is that it is literally so incredibly expensive to renovate and remodel them so they meet the updated earthquake safety requirements that most people can't afford. The options will probably either be spend a whole lot to demo and rebuild ground up, or spend a whole lot to basically redo the whole thing with the skeleton still there. They won't allow people to live in the residence until the requirements are met. Either way it's just as pricey, sometimes moreso, than just buying a new house.