Sesshomaru hands the broken Tenseiga to a grieving Towa, leaving Setsuna’s fate in her hands. Will Towa be able to bring Setsuna back to life?

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.