This feather is used for preparing sumi during Ro or Furo season.
Haboki (feather brush): When the Kama (kettle) is removed from the sunken fire pit (Ro) or the Furo, the Haboki feather brush is used to ritually clean the opening before beginning to re-arrange and add more charcoal to the fire; also, after charcoal and incense have been added, again the rim will be cleaned to make sure there is no ash or other dust left behind.
When picking the Haboki up, the end of the brush will be briefly touched to indicate its higher ranking than other charcoal procedure tools.
Two kinds of feather brushes are used. In winter the left side of the feather is wider than the right side. The Haboki used in summer is wider on the right side.