InuYasha (犬夜叉) is the titular character and one of the main protagonists of the series. Born to a dog demon father and human mother, InuYasha is a half-demon who initially wants to use the powers of the Shikon Jewel to become a full demon. After falling in love with Kikyo, the miko who guards the Jewel, he changes his mind and wants to become human so he can live with her, but Naraku manipulates both of them into believing they have been betrayed by one another. Kikyo is fatally wounded, but before she dies, she shoots an arrow through InuYasha to seal him onto a sacred tree. InuYasha remains in suspended animation for fifty years until Kagome Higurashi, Kikyo's reincarnation, pulls out the arrow and frees him. After the Shikon Jewel shatters, InuYasha and Kagome travel together to retrieve its shards. At first, he is hostile and uncooperative, but Kikyo's sister Kaede restrains him with a magical necklace that hurls him to the ground whenever Kagome gives the simple command word "Sit!" Initially wary of Kagome's resemblance to Kikyo, InuYasha grows to trust her as a friend and they eventually fall in love with each other. He also forms strong friendships with the other companions they gain. At the end of the series, InuYasha and Kagome acknowledge their love and are living together in the Feudal Era.
Due to his half-human nature, InuYasha loses his demonic powers and becomes human during the night of the new moon: his hair changes from white to black, and his fangs, claws, and dog ears are replaced by the normal human equivalents. As he is at his most vulnerable during this time, InuYasha is secretive about when it occurs, revealing it only to his most trusted companions.
InuYasha's sword, Tetsusaiga, was made from one of his father's fangs. Later in the series, one of InuYasha's fangs is welded into the sword. Tetsusaiga cannot be wielded by full-blooded demons, as its power is only unleashed when InuYasha uses it to protect humans. It also keeps InuYasha's demon blood in check, preventing it from turning him into a mindless killing machine when his life is in danger. Tetsusaiga's sheath can form a barrier to protect InuYasha from most attacks.
In the anime adaptation, InuYasha is voiced by Kappei Yamaguchi. In the English dub, he is voiced by Richard Ian Cox.
