Yurine is the youkai-priestess for Tokyo.
Ekou was the Karas for Tokyo during the Edo period, but when he turned down the "shadow path" she was forced to select new Karas. All Tokyo Karas since Ekou have fallen before him, and Otoha is Tokyo's last hope. Yurine holds the secret to a dark force empowering Ekou, but its exact nature is yet to be revealed.
There is one Yurine for every Karas.
All Yurines' seen throughout the series look practically the same only having a few differences. They all have jacket with giant zipper, other than that they differentiate from a few changes which are the blue scar tattoo, hair color, goggles, tights, skirts, and hair beads. The only hair color seen so far is pink and blue. They also have a tank top under their jacket. They are seen at about the same height and in some scenes have tails. The tails are most likely given because of there ability to turn into cat youkai.
They all speak and act as if in apathetic state.