Kagome Higurashi is a modern day young girl who lives with her family by the old Higure shrine. Unbeknownst to Kagome, she is the reincarnation of priestess Kikyo and posseses the "Jewel of Four Souls" The Shikon Jewel. One ill-fated day, Kagome locates an ancient well near her home and is abruptly transported through the well and into a feudal Japan, inhabited by demons. There, she encounters Inuyasha, son of a powerful demon father and a human mother, who is pinned to a tree by an enchanted arrow.
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.
While Miroku and Sango fight Naraku's demon puppet, Inuyasha and Koga continue their deadly battle, with Kagura planning to kill the winner.
Inuyasha and his companions come upon an orphan named Koharu, a young woman who believes she is in love with Miroku, after he helped her three years ago. When Koharu needs help again, they assist her and find her a home in a new village. When Naraku sends Kagura and Kanna to destroy Inuyasha and his companions, Koharu and the villagers become the new pawns in Naraku's devious plan.
Inuyasha and his group must defend themselves against an attack on multiple fronts. Kanna attacks Kagome, attempting to suck her soul into her mirror while Sango remains unconscious in the same room. Koharu tries to stab Miroku, while Inuyasha battles Kagura. Can Inuyasha use his Wind Scar to defeat her?
Inuyasha, though still recovering from his serious wounds, fights Goshinki, a demon who is eating an entire village.
Sesshomaru goes to a swordsmith, Kaijinbo, to get a new sword made from the fangs of the demon that broke Tetsusaiga, Goshinki. But something unexpected happens, and Kaijinbo attacks Inuyasha on the night of the new moon, when Inuyasha reverts to his human form.
Inuyasha, wielding a too heavy Tetsusaiga, tries to defend himself against Kaijinbo who has been possessed by Tokijin. Unbeknownst to Inuyasha, Sesshomaru is looking for Kaijinbo and the sword he had commissioned. Will Inuyasha be able to withstand his brother, when Sesshomaru reclaims Tokijin?
Naraku sends his two new incarnations, Juromaru & Kageromaru, to attack Koga, and also, Inuyasha and his companions. Can Inuyasha and Koga work together as a team to defeat these new foes?
As Inuyasha and the others recover from their battle with Juromaru and Kageromaru, Kagome goes home. Meanwhile, Naraku comes after Kikyo, and she must flee for her life.
Inuyasha and Kagome must sort out their feeings for each other, after Kagome has spied him with Kikyou, again. Who will Inuyasha choose?
While searching for Naraku's castle, Inuyasha and his group find Kohaku, who has lost his memory.
Sango and Kilala fight off demons in the woods, while Inuyasha and Miroku face off against Kagura, a horde of demons and Naraku's wasps. Meanwhile, Kagome faces Kohaku, who is being ordered to kill her by Naraku.
Sesshomaru learns from the wise tree-demon, Boku'seno that when Inuyasha transforms into a demon, his demon blood takes full control turning him into a mindless killing machine. Elsewhere, Inuyasha and the others arrive at a village that is ruthlessly being held under the control of the Moth Demon, Gatenmaru and his band of thieves.
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.
Totosai tells Inuyasha that piercing the heart of Ryukotsusei, the demon that gave his father his mortal wound, will make his Tetsusaiga lighter. Inuyasha then decides to kill Ryukotsusei.
Inuyasha fights Ryukotsusei with Tetsusaiga's ultimate attack: The Backlash Wave!