Yama, Kaimashita ~Isekai Gurashi mo Warukunai~山、買いました ～異世界暮らしも悪くない～; I Bought a Mountain: Living in Another World Isn't So Bad; I Bought a Mountain ~Living in Another World Isn't So Bad~

When I bought a mountain, I never expected it to be from another world! And while I was leisurely enjoying a countryside life suited to this strange realm, I unknowingly began making the mountain more powerful!? (Source: Amazon JP, edited)