Episode 28 (Hanyō no Yashahime)

The Barrier of Mount Musubi is the twenty-eighth episode of Hanyō no Yashahime, and the fourth episode of the second season titled "The Second Act."

Summary
The Half-Demon Princesses have at last reached the demonic-spiritual mountain of Musubi. What mysterious dangers and uncertainties await them? And will they each have the bravery and inner strength to let go of what they hold most dear to pass the trials that the demonic-spiritual shield has presented them with?

Plot
Outside Mount Musubi, which contains vast amounts of both demonic and spiritual energy, Jaken and Sesshōmaru wait. Jaken tells his lord and master that it is where the cat-eared teenage demon girl Rion has been sealed away for six long centuries. The Half-Demon Princesses become separated but Moroha is capable of entering through the incredibly strong demonic/spiritual energy shield due to possessing spiritual powers. Rion finally awakens and tells Moroha that she can find Towa and Setsuna, but only if she is willing to let go of what she holds most precious. The quarter dog-demon girl breaks through with her sacred arrow and enters the border between the mortal world and that of the Afterlife, where is confused at seeing the gigantic skeletal corpse, unaware it is her paternal grandfather. Inuyasha and Kagome Higurashi are shown to have come down to terms to their fourteen-year imprisonment in the demon graveyard. Inuyasha tells his human miko wife that the fang of his mighty Tessaiga is stirring because it is trying to tell him something important. As the spirit of Moroha continues to hover throughout the graveyard, her scared arrows suddenly become restless and becomes emotional upon glimpsing Inuyasha and Kagome, whom she recognizes from the picture that her Uncle Sōta had shown her all those months ago. Kagome is excited upon seeing her firstborn child as a teenage, to which Inuyasha expresses how glad he is that his own child has been living fine without their parental guidance and love.

Meanwhile, Towa is being tested by the voice of none other her middle school teacher Osamu Kirin, who informs her that she must let go of the modern era. However, Setsuna is taken to the Sacred Tree of Ages and finally meets the sleeping eighteen-year-old Rin within the unparalleled time-based entity very core. Setsuna then recalls how the song she plays on her violin was a memory that only her body could recall, realizing that she must have learned it from the woman she now sees. The Sacred Tree of Ages asks the half dog-demon girl how she feels getting to meet her mother again; explaining how her young human mother has not aged since being hidden within it for fourteen years since she gave birth to Setsuna and her elder twin sister.

Towa is taken to a facsimile of Tokyo, while Setsuna encounters Rin for the first time inside the Sacred Tree of Ages. Both Kirinmaru and the Tree of Ages are delighted to hear of the girls' morals and are appointed Guardians for Rion, who gives them a Kyūyōkon Root. Osamu Kirin continues to vouch for Towa's absences in exchange for unlimited access to the Shintō Shrine from within the Bone-Eater's Well once was, his place of birth.

Trivia

 * The flashback shows Tōkotsu's full body before the red skeletons in "Jakotsumaru of the Red Bone Palace" but only his right arm is seen.
 * The scene of Sōta showing the photo album to Towa from the "The Gateway to the Past" was reconnected with Moroha having seen it earlier as well, so she would recognize her parents if she ever found them.
 * Inuyasha and Kagome Higurashi make their actual debut here; albeit still trapped in the Demon Graveyard. Moroha finally knows where her parents have been since her birth fourteen years ago.
 * It is revealed that, like Riku, Kirin is an autonomous and sentient embodiment of Kirinmaru's own physical self, from the Beast King's right arm that was cut off by the Beast King Tōga of the West. As such, it was thrown into the Bone-Eater's Well and from there manifested as a human-looking man who was then absorbed into the modern era. His centuries-long presence, however, is gradually starting to cause rifts in the infinite space-time continuum.
 * It's been revealed that Kirinmaru's severed right arm was the first to be sent into the Bone-Eater's Well. Afterwards was the pure demon-spirit Saya within the autonomous demon spirit Sō'unga of Hell, then ninth grade middle-schooler Kagome Higurashi, who had consistently traveled backward and forwards between the five century-long timelines since her fifteen birthday.
 * The scene in which Moroha encounters Rion is reminiscent of that of the original anime's premiere, in which fifteen-year-old Kagome Higurashi had discovered the deeply sleeping Inuyasha on the trunk of the ancient and infinitely powerful Sacred Tree of Ages.

Errors

 * Tōga was erroneously carrying both Tessaiga and Tenseiga six centuries ago; further contradicting the knowledge of their origins (Tessaiga was created to protect Tōga's human wife, Izayoi, who was alive during the . And that Tenseiga was a cast-off of Tessaiga to maintain the unwanted and deathly powerful Meidō Zangetsuha attack/technique).
 * The Sacred Tree of Ages was stated to be 1000 years old and it was said that its wood was used to make the Bone-Eater's Well. Therefore, the Bone-Eater's well shouldn't have existed when Riku disposed of Kirinmaru's right arm.
 * Towa mentions that she had seen the young, pretty woman deeply sleeping within the Sacred Tree of Ages twice before in dreams alone (directly referring to "The Dream Gazing Trap" and "The Secret of the Rainbow Pearl"), but she seemed not come to the realization that she was indeed her biological mother back then.