"足" or "Ashi" is one of the features in the blade of a Japanese sword. It refers to the pattern where the temper line (沸 Nie) or the scent (匂 Nioi) extends from the edge of the blade towards the tip. This pattern appears as a line connecting the temper line or scent from the edge to the tip of the blade.

Different types of ""Ashi"" are named based on their characteristics:

- ""小足"" or ""Koashi"" refers to a short ""Ashi"".
- ""鼠足"" or ""Nezumiashi"" refers to a particularly short ""Ashi"".
- ""逆足"" or ""Sakaashi"" refers to an ""Ashi"" that is directed towards the tip of the blade.
- ""丁子足"" or ""Chōji Ashi"" refers to an ""Ashi"" that looks like a clove flower.

There is also a type of "Ashi" called "飛足" or "Tobiashi", which appears disconnected from the blade edge. Within this category, particularly short ones are called "葉" or "You".