

Inuyasha and his companions encounter Hakudoshi, who is in search of the remaining shard of the Shikon Jewel located in the Netherworld, before he escapes. Hakudoshi ends Entei's wild rampage when he arrives and slaughters Rengokuki, hence being chosen as its new master. Rengokuki meets Kagura, who quickly declines his offer in marriage. Inuyasha and his companions follow Entei and is led to Rengokuki, who has risen from his grave, but the two retreat when Inuyasha overpowers them. The half of The Infant that was guarded by Kagura transforms into Hakudoshi, the eighth incarnation of Naraku. Moreover, due to Entei's swiftness, it is left unharmed. Chaos ensues when the seal of Entei is broken. Kagura brings both halves of The Infant to Kanna, who keeps one of the halves. However, the monk slices The Infant in half. Kagura and The Infant approach the monk to attack him. A legendary monk is known for sealing a swift demon horse known as Entei, and its demon master named Rengokuki, in the mountains. When Inuyasha and his companions come upon a wrecked village, they find out that the priest of the village was murdered by Kagura and The Infant. Tsukiyomi gives Inuyasha and Kagome a chance to destroy the demonic halberd once and for all. Akitoki confesses his unrequited romantic love for Kagome, defending against an attack by Hoshiyomi. However, Hoshiyomi killed Tsukiyomi as payment of betrayal.

Tsukiyomi sealed Hoshiyomi within the shrine, and separated the halberd into two blades. Hoshiyomi wanted to forge the Naginata of Kenkon in order to fight alongside Tsukiyomi, but he became possessed by the demonic influence of his overwhelming weapon. The spirit of Tsukiyomi returns and possesses Kagome to reason with her old lover. With the complete Naginata of Kenkon in his possession, Hoshiyomi is virtually unstoppable. "Eien no Omoi Kenkon no Naginata" (永遠の思い 乾坤の薙刀) Hoshiyomi summons the two blades together to form the Naginata of Kenkon. Miroku uses his Wind Tunnel to vacuum the four ninja yōkai into the vortex. He believes that by reuniting the two blades, he must kill humans to save humankind.

The bitter Hoshiyomi reveals to Kagome his own tragic close romantic relationship with a high-ranking human priestess named Tsukiyomi. Each are encountered by one of the four ninja yōkai, proving to be worthy opponents, as Inuyasha's group struggle to defeat them. The rest of Inuyasha's group have been scattered by the pentagram barrier surrounding the shrine created by Hoshiyomi. Hoshiyomi holds Kagome Higurashi captive, to unite the Ken Blade with the Kon Blade. The ending themes were "Come" by Namie Amuro for episodes 139-147, "Change the World" by V6 for episode 148, "Brand-New World" by V6 for episodes 149-166, and "My will" by Dream for episode 167. The opening themes for this season were "One Day, One Dream" by Tackey & Tsubasa for episodes 139-153 and "Angelus" ( ANGELUS -アンジェラス-, Anjerasu) by Hitomi Shimatani for episodes 154-167. The English dub of the last season was broadcast on Cartoon Network as part of its Adult Swim programming block from March 29, 2006, through October 27, 2006 The anime is licensed for release in North America by Viz Media. The season continues the half demon Inuyasha's and the high school girl Kagome Higurashi's journey alongside their friends Shippo, Miroku and Sango to obtain the fragments of the shattered Jewel of Four Souls, a powerful jewel that had been hidden inside Kagome's body, and keep the shards from being used for evil. Based on the manga series of the same title by Rumiko Takahashi, the anime was produced by Sunrise. The final season of the anime series Inuyasha aired in Japan on Animax from January 26, 2004, through September 13, 2004.
