The Celestial Brush was named after a poem written by Ishaku. It is actually the tip of Amaterasu and Chibiterasu's tails coated in ink. Many different brush strokes are available from different Celestial Brush gods. Each brush stroke has a different effect, known as Celestial Brush techniques.
- When designing a mask in the Moon Cave, Issun's brush is used instead of Amaterasu's.
- In the fight against Ninetails, it will draw its own attacks on Amaterasu's canvas. It can only do so if the brush screen remains open for too long. As an added note, Ninetails draws with red ink.
- This is also true in the fight with Dark Chibiterasu, who can paint over Chibiterasu's drawings, should he take too long and vice versa. As with Ninetails, Dark Chibiterasu draws with red ink.
- In the fight at Wawku Shrine, Shiranui will assist Amaterasu with attacks drawn on its canvas. Its brush techniques are more powerful versions of Amaterasu's. Its ink is also colored gold instead of Amaterasu's black ink.
- When Amaterasu and Chibiterasu loses all of their ink, they also lose their Divine Instrument (and any Karmic Transformers they might have equipped) and take the appearance of a plain white wolf. This is the same appearance most humans see them as, since they do not believe in the gods. In this state, both attack using kicks and bites.
- In the battle against the 5th form of Yami, Amaterasu's Celestial Brush will change into Shiranui's brush.
- Issun's ink in Ōkami was black, whereas it is red in Ōkamiden.