The idea of a “used house” sounds strange for me. It is perfectly normal in Canada to buy a previously owned house. But as you may already know, in Japan, only the land has value. I won’t cover for now all the detail of what’s involved when buying a house but I will just say that Izu land and house are relatively cheap compared to more densely populated area. To live in Izu is also an economic decision. Think about it when you return to your apartment with no kitchen. Is this healthy? Does it make sense? If feel like taking a look, check out this website about Izu houses for sale
