Thats the point. From the article: "The practice dates back to the 1700s, when gamblers known as bakuto would accept a person’s severed finger in order to set

Thats the point. From the article: "The practice dates back to the 1700s, when gamblers known as bakuto would accept a person’s severed finger in order to settle a gambling debt. The little finger on the left hand was chosen as its removal hampers a person’s grip on their sword (katana), weakening them as an opponent."