What is the word for 'human' in Japanese?

The Word you are looking for is "Yokai." A "Yokai" is an animal spirit, while a "Mononoke" is a nature spirit, there is a difference between the two. The anime "Inuyasha" focuses around the world of the Yokai; Inuyasha himself is a "Hanyo," half Yokai, half human. The Word "demon" is a mistranslation; the supernatural creatures you see in Inuyasha, are all animal spirits. Naraku for example is a spider, Inuyasha and Shippo are both canines (Shippo is a fox), and, as a generic rule in the anime, cute mammal Yokai are good guys, while "gross" animals such as reptiles, amphibians, and insects, are all bad guys. Women don't like bugs or reptiles. lol. Inuyasha was made by a woman, so, its only natural that "cute" animals would be "good guy" Yokai. Also one creature women loath most, is the spider, so its only natural that in Inuyasha, the main villain was, imagine that, a spider Yokai.