After recovering from Shinobu's attack, Nanao's next step is to learn how to protect herself in the event of future catastrophes, but the Benitsubaki brothers have other concerns. Seeing Nanao and Yako's happy life together makes Takaya long for a marriage of his own, but his mother is less than thrilled about the idea. As the Onmyo captains convene from all over the empire, two questions are on everyone's mind: who is responsible for the ayakashi Shinobu summoned? And what really happened to Nanao on that fateful night all those years ago?