Kamaitachi, the 'sickle-weasels', are a type of youkai (Japanese supernatural creatures of various origins and traits). They work in a group of three siblings to attack travelers on the road. The eldest knocks down the traveler, with a club, stunning him. Then the second cuts a deep gash on the traveler with its long claws, which is near-instantly healed by the youngest's healing balm. Thus the traveler ends up very confused why an apparently normal gust of wind suddenly left a huge, bloodless scar on his person.