You should read your insurance contract carefully so you aren’t hit by any nasty surprises.
Earth movement in general - from landslides to sinkholes to shifting foundations - is excluded from most home insurance policies.
Earth movement in general - from landslides to sinkholes to shifting foundations - is excluded from most home insurance policies.
Many non Japanese who are buying in Japan without understanding this fundamentally different aspect of real estate in Japan do so at their own risk.
I don't know specifically about mines or sinkholes, but I don't think they are generally excluded. However one difficulty would be that buildings are generally insured up to the value of the rebuilding cost, IE what it would take to put the building back after it was completely destroyed. But in the case of a mine or sinkhole, the land itself may also be unusable. In an expensive city the rebuild cost may be only a fraction of the cost of buying an equivalent home, including the land it sits on.