Episode 1 (Hanyō no Yashahime)

Inuyasha: Since Then is the first episode of Hanyō no Yashahime.

Synopsis

 * It turned out that after the last return of Kagome, the Bone-Eater's Well was sealed and is no longer in working order, so it is not known how the modern girl Towa was able to travel to the past.
 * For the first time, a mysterious four-eyed owl demon appear. He takes away the surviving small part of the Root Head, who Inuyasha and Kagome consider destroyed. Many years later, Moroha and Setsuna pursue the same owl demon for as yet unknown reasons.

Summary
A mysterious half-demoness princess named Towa Higurashi was captured by a shogunate adviser from Kantō region, who inquires her about some items from the future in his possession, including a book from the Reiwa Era and the seat from Kagome's bicycle, but Towa refuses to comply, certain that sharing info from the future will alter the past. The story then shifts back to six months after Kagome started living with Inuyasha and her other closest friends and their young children, two of which are identical twin sisters. Inuyasha and Miroku fight the Root Head, a demon who was sealed by Kikyo many decades ago, but the enemy escapes.

Completely unaware that Kikyo has been dead for decades but has had her immense spiritual powers reborn in her modern-day reincarnation, Kagome, the Root Head attacks Kagome and she joins Inuyasha, Miroku, and Sango to destroy it, unaware that a small part of the demon has survived. Back to Towa, she is rescued by a demon slayer named Setsuna and a demon bounty hunter named Moroha, who realize that the lord attendant is a demon as well and chase after it but before departing, Towa confiscates the book and the seat from the lord.

Differences from the manga

 * Miroku and Sango's children were given names. In the manga, their names are not revealed.
 * The manga did not feature the demon Yotsume that secretly watched Inuyasha, Kagome and their friends as they fought against the awakened Ne no Kubi.

Episodio 01 (Hanyo no Yashahime)