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

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 decides to return to the feudal era to help Setsuna regain her memories. The trio enter the corridor leading to the feudal era, but within it awaits the spirit of a certain priestess.

Safely back in the feudal era, Moroha heads to the corpse dealer to claim her bounty. Meanwhile, Towa and Setsuna take on a request to slay Jakotsumaru, a boy who has been extracting bones from humans and beasts in order to revive his father, the demon beast Tokotsu.

On her way to search for the Dream Butterfly, Towa meets a strange young man named Riku. Towa offers him an apple, and in thanks, Riku presents her with the genuine Kikujumonji sword.

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

Setsuna opens up to Towa about the hidden village for half-demons where she was raised for most of her childhood.

On the night of the new moon, Riku pays Towa a visit to chat. Unfortunately, he’s not the only one planning to drop by.

Setsuna is kidnapped by Princess Aiya, daughter of the deputy shogun. Wanting to escape her studies, Princess Aiya begs Setsuna to be her body double for a day, but the princess’s new tutor turns out to be Hisui posing as his older sister Kin’u!

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.

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.