Episode 4 (Hanyō no Yashahime)

The Gateway to the Past is the fourth episode of Hanyō no Yashahime.

Synopsis
Moroha discovers a way back to the Feudal Age, striking a deal with Root Head she intends to break.

Setsuna bonds briefly with Moe Higurashi, learning to play the violin. Towa spends one last night with her adoptive family

The Tree of Ages informs the trio of their dog-demon heritage, and urges them to seek and defeat the demon lords Kirinmaru and Sesshomaru. Towa and Setsuna refuse, and the trio are left to battle Root Head.

Summary
The three girls resolve to return to the past to capture the Dream Butterfly and restore Setsuna's ability to sleep. As they spend a few days in the modern world, Setsuna masters the violin and becomes fond of it, while Moroha discovers Root Head in the Tree of Ages and negotiates with him to reopen the portal in exchange for their Rainbow Pearls. Setsuna takes the violin with her while Moroha brings a massive bag of modern supplies (which she bought by stealing Sota's credit card, leaving him with a huge bill). Grandpa Higurashi gives Moroha a few gifts like a kappa's foot. Towa bids farewell to her family, with Mei begging the three to promise to return, and the three jump into the portal. They are interrupted by the Spirit of the Tree of Ages, who takes Kikyo's form. She asks them to slay Kirinmaru, an old rival of their grandfather, the Great Dog General, who plans to take over Japan, and Sesshōmaru, whom she says walks a similar path to Kirinmaru. Setsuna refuses, saying she doesn't care about the father she never met, while Towa doesn't want to kill her father on principle. The spirit transports them to Root Head, who attacks them for their Rainbow Pearls.

Root Head is able to drain their respective dog-demon powers, but Moroha throws the kappa's foot into his eye to weaken him. They defeat him and arrive in the past to be greeted by Kaede, Kohaku, and Hisui. Towa realizes that without Root Head, they have no means to return to the modern world. Meanwhile, the Spirit of the Tree of Ages watches over an adult Rin, who is in suspended animation, with the Dream Butterfly circling overhead. While commenting on the girls' refusal to heed her request, She tells Sesshōmaru that if he forsakes Rin, she will never wake up. She then comes to realize that to remain unchanged may be for the best.

Trivia

 * Grandpa Higurashi offers Moroha the same alleged mummified foot of a kappa he tried to offer Kagome for her 15th birthday in the very first episode, and Moroha makes the same expression Kagome did, but otherwise has the opposite reaction. Moroha noted that such an item is treasured (due to coming from when the demon is still alive); it later DOES provide good luck by serving as a distraction.
 * Moroha stole Sota's credit card to buy supplies, much to his utter horror due the massive bills.
 * Moroha is to blame for the book of future knowledge that was discovered by Towa's captors in the first episode.
 * The path used to go back to the feudal era is similar to the spirit road often used in Kyoukai no Rinne.
 * The Sacred Tree mentions the sealing arrow on its trunk, which Kikyo had demonstrated to her younger sister Kaede in "The Tragic Love Song of Destiny, Part 2." However, it does not inform Moroha that her father had been sealed on its trunk for half a century.