Delimbing tool
When a mysterious object comes with a sharp edge, your first guess would probably be an old weapon of some sort. That, or maybe a garden tool. The person who uploaded this image asked the helpful community whether they could explain what this tool was. The only piece of information they provided was that it came from Japan.
Everyone’s first guess was that it was an ax, though it hardly looked like one. Later on, another commenter said it was a delimbing tool that gardeners use to remove branches from trees. The razor-sharp blade can cut through thick branches with just one swift pass.