Something wicked lurks in the Man-Eating Pond, devouring any human, beast or bird that comes near. Towa and Setsuna meet Hikomaru and Chiyo, siblings who lost their parents to the pond.

Zero removes the seal that Miroku placed on Setsuna to suppress her demon powers, awakening the latent demon blood within.

Rion used to travel the world with her father Kirinmaru, but one day, her soul was sealed deep within Mount Musubi. Longing for freedom and peace, Rion asks Setsuna to sever the thread of fate that connects her to her father.

Kirinmaru takes the Black Pearl from Moroha and demands that she bring Akuru to him. Towa and Setsuna try to lend a hand, but Sesshomaru arrives at the scene to take on Kirinmaru instead. Meanwhile, Rion and Riku head to Mount Musubi.

Towa, Setsuna, and Moroha must save Rion, who has linked her fate with the Grim Butterfly, but Osamu Kirin stands in their way. Kirin declares that he and Rion should reign over the world in order to bring about true peace.