Tsugumi Izuriha
Sasame’s sister with the same appearance as Sasame except with longer hair. She usually appears with the corpse, wearing a white sleeveless dress.
Tsugumi was a priestess from Yomijima, but unlike the other children, she was left behind in the Lightless Realm. This causes her to bear hatred to the other children and she also vows to continue her revenge on IX. She has been living in the Lightless Realm ever since by surviving on the Arbornine.
She saves Akashi in episode 15, preventing him from turning into necrometal as she still harbors feelings for him since childhood.