In the present day, a demon emerges through the Sacred Tree at Higurashi Shrine with Setsuna, Towa’s twin, and the bounty hunter Moroha in tow. Towa, Setsuna, and Moroha struggle to battle the demon, whose powers have been strengthened with two Rainbow Pearls, but seeing Setsuna in trouble awakens Towa’s latent demon powers.

Towa, Setsuna, and Moroha are left to confront Kirinmaru, but in the face of overwhelming power, they must pay a great price.

In the present day, Osamu Kirin sees the Grim Comet approaching. Meanwhile, in the feudal era, Towa’s life is in danger after she uses her Zanseiken. The Spirit of the Tree of Ages orders the half-demon princesses to go destroy the Grim Comet.

Setsuna directs Towa and Moroha as they continue to sever Rion’s threads of fate. Each time a thread is severed, more of Rion’s true feelings are revealed. As Kirinmaru fights Sesshomaru, he realizes the real reason he lost Rion.

The feudal era is saved from the Degenerate Age. Inuyasha helps repay Moroha’s remaining debt. Towa and Setsuna receive kimonos from their mother, Rin. Towa, Setsuna, and Moroha accept a demon-slaying request from a mysterious man.