Kitsune is the Japanese word for fox. Foxes are a common subject of  Japanese folklore. Stories depict them as intelligent beings and as possessing  magical abilities that increase with their age and wisdom. Foremost among these is the ability to  assume human form. While some folktales speak of kitsune employing this ability to trick others — as foxes in folklore often do — others portray them as faithful guardians, friends, lovers, and wives.

Foxes and human beings lived in close proximity in ancient Japan; this companionship gave rise to legends about the creatures. Kitsune have become closely associated with  Inari, a  Shinto kami or spirit, and serve as his messengers. This role has reinforced the fox's supernatural significance. The more tails a kitsune has — they may have as many as nine — the older, wiser, and more powerful it is. Because of their potential power and influence, some people make offerings to them as to a deity.

(Source: www.wikipedia.org)