Inuyasha is half demon and half human. His father was a demon, and his mother a human. Because he is a half demon, every New Moon of the month, he turns into a human for one night. Until the sunrise of the next day, he remains in his human form. In this form, his hair turns black, the dog ears disappear, his eyes turn brown and his claw-like nails turn into normal human nails.

Fifty years ago he was put into statis by an enchanted sealing arrow from Kikyou. Inuyasha is after the Shikon no Tama. This is because if he gets the Shikon no Tama, he can become a full demon, with full demonic powers. Inuyasha is brought out of his statis of fifty years by Kagome. Because she is believed to be a reincarnation/descendent of Kikyou, she is able to pull the arrow out, ending the enchantment and set Inuyasha free. Although it appears at first that Inuyasha hated Kikyou, we find out it isn't entirely true...

Inuyasha travels with Kagome, looking for the pieces of the Shikon no Tama. Along the way they make new friends, and companions join their travels too.

Inuyasha has several attacks. The number of his attacks increase as his sword, the Tessaiga, increases in power, reaching its full potential. The following are his attacks (in the anime) so far...

Sankontessou (non-sword attack)
Hijinkessou (non-sword attack, where IY uses his own blood)
Tessaiga (IY's normal sword attack)
Kaze no Kizu (IY's special sword attack)
Bakuryuuha (IY's SUPER special attack where he can use the kaze no kizu anytime)

No matter the situation, Inuyasha protects Kagome. Even though he always says she's bothering him by being there, it is her presence that makes him stronger. When Kagome isn't there, Inuyasha doesn't seem to reach his full potential. Whenever Inuyasha is in human form, the Tessaiga remains a regular sword, and doesn't transform. Usually Inuyasha doesn't like to think he is human once a month, and usually goes beyond his limits, getting quite banged up in the process...

When it comes between Kikyou and Kagome, Inuyasha has an internal conflict about who is the one he cares about and loves. Sometimes he thinks it's Kikyou, other times Kagome. Time will have to tell us who he chooses. Either the real, living Kagome, or the resurrected, half-living Kikyou...either way, Inuyasha definitely has human emotions, making him a kind, caring half demon.