Utilizing the ability to carve one's memories into the eternal storage of time of the Origin Mirror and the Ultimate Origin Mirrors' amplified divine powers, Amaterasu can warp from an Ultimate Origin Mirror mirror to any of them in areas she has visited. This technique is far better than using Mermaid springs in strategical warping, since in most human-inhabited locations, only Ultimate Origin Mirrors are present. Also, with Mist Warp, Amaterasu can obtain two StrayBeads that are in Rocky Areas and cannot be reached by conventional means.
To use Mist Warp, draw an X over an Ultimate Origin Mirror while directly facing it by stepping on the circular area of reflection at the mirror's base.
After the defeat of Blight, Amaterasu can trade Demon Fangs for the Emperor to obtain Holy Artifacts, and one of the items for sale is the Fog Pot. By buying this Holy Artifact, Kasugami grants Amaterasu the Secret Brush Technique of Mist Warp.
Spoilers end here.
Even though Mist Warp is not present in Ōkamiden, it is still possible to warp to places Chibiterasu has visited via the powers of Kagu's Charm. In fact, it is also possible to warp through time, as there are Ultimate Origin Mirrors at Kamiki Village and Shinshu Field in the past.