Episode 1 (Hanyō no Yashahime)

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

Synopsis
A young half demon named Towa was told a tale from ten years prior about a priestess and a half demon who battled demons.

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 flashes back to six months after nineteen-year-old Kagome started living with Inuyasha and her other closest friends and their young children, two of which are identical twin sisters. Gyokuto and Kin'u were interested when Kagome told them how effective the Kikyō root was, but they wished it was a snack instead. Inuyasha and Miroku fight the Root Head, a plant demon who desired the Shikon Jewel and was then sealed by Kikyō many decades ago, but the enemy escapes.

Completely unaware that Kikyō 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 by attaching itself to the Sacred Tree of Ages itself.

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

 * The names of Miroku and Sango's children are not revealed in the manga.
 * The manga did not feature the yōkai Yotsume that secretly watched Inuyasha, Kagome and their friends as they fought against the awakened Ne no Kubi.
 * Ne no Kubi's defeat was slightly different in the anime and the manga. In the manga, Ne no Kubi was seriously wounded by Kagome's sacred arrow and destroyed forever by Inuyasha's Kaze no Kizu. In this episode, after their combined attack, Inuyasha uses Meidō Zangetsuha which sends the demon to the netherworld.

Episodi 1 (Hanyo no Yashahime) Episodio 01 (Hanyo no Yashahime)