Hanyō

Hanyō (half-demon in english terms) is a mix between a Human, and a Yōkai.

Description
A Hanyō is born when one of the parents is a Yōkai, and one a Human. A Hanyō typically possess the ability to become a Yōkai if under a considerable amount of pain, suffering, or loss, and with the power of the Jewel of Four Souls have the ability to become a full-blooded Yōkai.

Naming
The 'yō' is derived from Yōkai.

Power
While a Hanyō can never be as strong as the demonic parent without becoming a Yōkai, most Hanyō seem to be powerful enough to not only deal with any human hostilities, but also to easily dispatch most Yōkai. It seems as if the only demons that have Hanyō spawn are the Yōkai powerful enough to diluting their power with Human blood would still leave them better of than the majority of demons. InuYasha is a prime example of this.

Impurity
As people, half-demons are often outcasted by their human brethren because of their demon heritage, deeming them monsters while their demon kin rejects them due to their human blood, considering them weak. In effect, half-demons are outcast for belonging to neither race. All of the half-demons that have appeared throughout the story have sought to remedy their 'impurity' by using the Shikon Jewel to either become a full-demon or a full-human.

Adittional Information
In the movie, InuYasha: Fire on the Mystic Island, there is a secret haven known as Horai Island where demons and humans live together in peace, raising their half-breed offspring who are accepted by all.

Know Half-Demons

 * Naraku
 * InuYasha