Unable to discover the secret to reaching Level 6, Hishigata tries a new approach by recruiting Esther Rosenthal, a necromancer. Esther and Hishigata's sister, Hirumi, become fast friends, but Hirumi's secret may jeopardize that friendship.

While Hishigata continues to bleed out from his stab wound, Hirumi opens her eyes and seems to be her normal self. However, as her Level-6 transformation progresses, it becomes clear that not everything about Hirumi is as it appears.