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.

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.

Jaken recalls that fateful day fourteen years ago, when Zero placed a curse on Rin that would make her slowly rot away to an excruciating death. The three girls search for Bokusen-Oh, who may have a lead on the whereabouts of Towa’s new weapon.

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

Towa is consumed by rage and loneliness. Setsuna tries to stop her from killing Zero because the curse on their mother cannot be lifted unless Zero lets go of her regrets. Sesshomaru gives Moroha the Black Pearl.

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.

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.