Towa Higurashi learns about an incident that took place decades ago involving a half demon named Inuyasha and a priestess named Kagome.

After fleeing from the deputy shogun’s estate, Yotsume borrows the power of a Rainbow Pearl to unleash his Dream Gazing spell upon the Half-Demon Princesses, who are hot on his trail.

The truth behind the night that sealed the fate of Towa, Setsuna, and Moroha’s parents is finally revealed.

The three girls arrive at Mount Musubi but are trapped by a powerful barrier. Moroha manages to escape and runs into something unexpected.

Moroha learns about her parents’ battle against Shogen Mamiana, the sealing of the Full Moon Raccoon Dog, and Takechiyo’s exile from his clan. Setsuna is attacked by the snow demon Yukinyudo. Zero targets Towa on the new moon.

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.

Inside the Black Pearl, Moroha is finally reunited with her parents, Inuyasha and Kagome. Inuyasha begins to see a way out of the Black Pearl. Meanwhile, Kirinmaru’s attack leaves Sesshomaru gravely injured.

Wanting to prove his strength, Kirinmaru faces off against Sesshomaru. Towa summons the Tenseiga. Shippo waits for Inuyasha and the others at Gozu and Mezu’s gate.

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.

Inuyasha and the others have their hands full with the evil spirits pouring out of the burning Windmill of Time. The three girls and Osamu Kirin try to stop the Grim Comet from falling to the earth.

Osamu Kirin brings the Grim Comet to the feudal era. He convinces Rion that they are both hoping for the same world and promises to make it a reality. Meanwhile, Towa, Setsuna, and Moroha are stuck in the present day.

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.

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.