On her way to search for the Dream Butterfly, Towa meets a strange young man named Riku. Towa offers him an apple, and in thanks, Riku presents her with the genuine Kikujumonji sword.

The demon Nikosen was a sage before evil consumed his soul. Konton orders him to kill the Half-Demon Princesses. Towa struggles as her demon powers fade and she turns into a human.

When a demon begins to devour virtuous monks and Shinto priests in the region, Hisui is assigned to guard his father, Miroku, who has been undergoing harsh training for the past two years.

The deputy shogun’s daughter Aiya offers to employ the demon slayers if they win in a battle against the bounty hunters.

Having restored Setsuna to life and recovered from her exhaustion, Towa finds herself alone as Setsuna and Moroha begin searching for the mystical root needed to forge Towa a new sword.

Zero sets a trap in the garden of Nanahoshi, a demon who feeds on sadness. Kirinmaru pays Towa, Riku, and Rion a visit. Kohaku, Hisui, and Setsuna assist the chief of the demon slayers in the north.

Kohaku and the demon slayers struggle to put out the fires caused by the Flame Bulls. Mayonaka, who used to be a local deity, demands the people of Gokoku Village hand over the town’s divine object.

Moroha and Takechiyo strike back against Shogen Mamiana. Setsuna experiences her first New Moon. Towa is trapped by Nanahoshi’s eternity bugs.

Zero unearths Towa’s sadness about growing up in the modern world and corners her with her memories of loneliness and suffering. Sesshomaru appears before the demon slayers and commands Setsuna to pay the Tree of Ages a visit.

Towa, Setsuna, and Moroha must save Rion, who has linked her fate with the Grim Butterfly, but Osamu Kirin stands in their way. Kirin declares that he and Rion should reign over the world in order to bring about true peace.

Setsuna directs Towa and Moroha as they continue to sever Rion’s threads of fate. Each time a thread is severed, more of Rion’s true feelings are revealed. As Kirinmaru fights Sesshomaru, he realizes the real reason he lost Rion.

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.