Inuyasha, once again, transforms into a demon when faced with Gatenmaru's murderous attack against himself, Miroku, and the helpless women of a village. Sesshomaru then appears to see if what Boku'seno told him about demon Inuyasha was true.

Kagome is able to pull out the Tetsusaiga. Sesshomaru tries to kill her, and Inuyasha is angered and fights to protect Kagome. His will to protect a human changes the Tetsusaiga into its true form, a fang sword.

Kikyo is revived when Kagome's soul flows into her. She tries to kill Inuyasha, but Kagome takes back her soul. Fifty years ago, Kikyo wanted Inuyasha to use the Shikon Jewel to become human. But on the day of their promise, someone who looked like Inuyasha fatally injured Kikyo. Inuyasha realizes that there is a mysterious person who made them fight.

Half demon Inuyasha's secret is that he becomes human once a month. That day, Inuyasha and the gang meet Nazuna and stay at a mountain temple. They fall into Kumogashira's trap and the sacred jewel shards are taken away from them. Inuyasha is injected with poison!

Sango, a demon slayer, is invited to Hitomi Castle along with her father, the leader of the demon slayers, and her younger brother, Kohaku. But it is a trap. Meanwhile, the undefended village is attacked by a horde of demons and annihilated. Naraku takes the Shikon Jewel shards that they had been gathering and leaves.

Sango fights Inuyasha, believing him to be her enemy. Naraku's plan is to have her fight to the death using the power of the Shikon Jewel shard. But Sango listens to Kagome and is no longer suspicious of Inuyasha.

In feudal Japan, the half demon Inuyasha was sealed away by the priestess Kikyo. Many years later he is revived by Kagome, who has slipped through time from the present day. Kagome is surprised when the sacred Shikon Jewel, which makes demons stronger, emerges from a cut on her body.

Kagome has returned to the present day and is relaxing in her home when Inuyasha comes looking for her. Some of Yura's demonic hair is on his body. Kagome and Inuyasha return to feudal Japan to exterminate the Yura of the hair.

Kagome learns that Inuyasha is a half demon, born of a human mother and a dog demon. Inuyasha's half brother Sesshomaru appears, looking for the tomb of their father. In order to manipulate Inuyasha, he brings Inuyasha's dead human mother with him. But the woman turns out to be a demon known as a muonna.

The muonna makes Inuyasha reveal the location of his father's grave. Sesshomaru removes Inuyasha's right eye (the black pearl) and opens the entrance to the grave. Kagome is angered by Sesshomaru's cruelty. She goes with Inuyasha after Sesshomaru. Inside their father's tomb is a memento of Inuyasha's father, the sword Tetsusaiga.

Miroku, a womanizing delinquent priest, has been collecting Shikon Jewel shards and steals Kagome's shards. Inuyasha tracks him down and confronts Miroku to get the shards back. Miroku fights back with his priestly powers and the wind tunnel in his hand that he was cursed with.

Naraku appears before Sesshomaru and lends him an arm with a sacred jewel shard embedded in it. Sesshomaru attaches the arm to himself and appears before Inuyasha and the gang to steal the Tetsusaiga.

Sesshomaru wields the Tetsusaiga with his borrowed arm against Inuyasha, who fights back with his scabbard. When the two strike each other at the same time, Inuyasha gets up close to Sesshomaru, rips off his arm, and gets back the Tetsusaiga. When Inuyasha learns Naraku's plan, he fears that Kagome might die.

After Miroku sucks a mantis demon into his Wind Tunnel, the demon manages to rip the tunnel. Panicked, Miroku returns to the home of his mentor, Mushin, to repair it. Haunted with memories of his father's death, Miroku must come to terms with his Wind Tunnel as demons attack Mushin's temple.

Naraku uses one of Sango's fellow demon slayers as a bargaining chip to try to persuade Sango into giving him Inuyasha's sword, Tetsusaiga.

In the hopes of saving Kohaku, Sango steals Inuyasha's Tetsusaiga and hands it over to Naraku. However, a battle against Naraku soon ensues.

While looking for an antidote to cure the ailing Kilala, Inuyasha and Kagome come across the herb garden of the half-demon, Jinenji, who is constantly bullied by the prejudiced locals.

Inuyasha and the others stumble across a cave full of demons fighting to the death. They soon discover that Naraku is using to find a new demon to integrate into his being. However, the large demonic aura brings Kikyo into the mess.

Acting under Naraku's request, Kikyo traps the Inuyasha gang with an illusory mist, causing them to have nightmarish visions.

Inuyasha and the others are introduced to Totosai, the swordsmith who forged Inuyasha's Tetsusaiga and Sesshomaru's healing sword, Tenseiga.

Inuyasha and Sesshomaru continue fighting for the Tetsusaiga. After the fight, while Sesshomaru is recovering, a little orphan girl, Rin, tries to bring him food. When her village is attacked by wolf demons, Sesshomaru returns the favor and helps Rin. Meanwhile, Kagome senses a jewel shard. Inuyasha and gang follow her lead to the massacred village, where they are quickly surrounded by wolves and Koga.

When Koga, a wolf demon, kidnaps Kagome and Shippo, Inuyasha, Miroku and Sango go on a rescue mission. But there's another foe they must defeat first, before they can reach their kidnapped companions.

Inuyasha and the group must battle the Birds of Paradise, before they can reach the wolf den. Meanwhile, back at the den, Koga expresses his true feelings for Kagome. When the final battle with the Birds ensues, will Inuyasha's jealousy cost Koga his life?

Kagome has returned home from the Feudal Era after an argument with Inuyasha. While waiting for Inuyasha to apologize, she spends time with her friends and Hojo approaches her, once again. Meanwhile, Inuyasha gets some advice from Kaede on the situation.

While Inuyasha's gang follows a demon bear with a jewel shard, Koga meets with some demons from the northern pack who tell him about their plan to storm a castle where a man has many jewel shards. When the chase leads Inuyasha and his comrades to the castle, they meet up with Koga, who is furious at the slaughter of the wolf demons.