Extra Boss, and Yukari's shikigami. She does Yukari's work for her while her master sleeps. Her main ability is control of shikigami.
Yukari sleeps 12 hours per day and is only awake from sunset to midnight. On top of that, she hibernates through winter. Because of that, Ran takes care of Yukari's work while she's asleep.
Ran has been a shikigami for quite long time, so she's more powerful than ordinary youkai. For that matter, she has enough power to possess her own shikigami. Perhaps she has already forgotten that she herself is a shikigami.
Every year, when cherry blossoms are about to bloom, she visits the Netherworld for flower viewing. The cherry blossoms seemed to be lasting somewhat longer than usual this year. Just as she was considering that, some living humans dropped in. She watched them with interest for a few moments.
She later heard that her shikigami had been defeated by them, so she plotted a little revenge.
In truth, she is a fox turned youkai. Like Chen, her shape is unchanged and she has a well-rounded personality. Even without looking closely, it's obvious that she has several tails. As a matter of fact, when it matters, she has plenty of power even without support from a shikigami.
Through all these events, her master continues to sleep.