The art in "Ōkami" is highly inspired by Japanese watercolor and wood carving art of the Ukiyo-e style, such as the work of Hokusai. "Ōkami" was originally planned to be rendered in a more photorealistic 3D style, but Clover Studio determined that the more colorful sumi-e style allowed them to better convey Amaterasu's association with nature and the task of restoring it. The change was also influenced by limitations in the PS2 hardware to render the photorealistic 3D graphics. As a result of the switch to the watercolor style, the idea of the Celestial Brush came about. Atsushi Inaba, CEO of Clover, noted that "once we fixed ourselves on a graphical style and got down to the brushwork, we thought 'Wouldn't it be great if we could somehow get the player involved and participate in this artwork instead of just watching it?' That's how the idea of the Celestial Brush was born". Original concepts for enemies included the use of dinosaurs, but the designs settled onto more demonic characters.