This is just one of the many initiatives by the government or a local body to give away houses. The population in remote areas of Japan (aside from tourism) is declining quite fast.
I've had friends who have bought houses for as cheap as $600 in remote areas of Japan. [1]
If you are interested in owning a house in Japan then Okutama (a town close to Tokyo) is giving away houses with certain conditions. [2]
There are at least five other programs scattered around the Kyushu island and around the Tohoku region. You may want to check areas affected by natural / man-made disasters such as Rikuzentakata, which are "reviving" its cities or towns.
If you are a tourist you'll get accommodation and travel tickets to these "reviving" towns (free of charge) as well (just need to know where to look). [3]
[2] https://www.japantimes.co.jp/news/2018/11/04/national/social...