Kitsunetsuki (狐憑き or 狐付き; also written kitsune-tsuki) literally means the state of being possessed by a fox. The victim is always a young woman, whom the fox enters beneath her fingernails or through her breasts.In some cases, the victims' facial expressions are said to change in such a way that they resemble those of a fox. Japanese tradition holds that fox possession can cause illiterate victims to temporarily gain the ability to read. Though foxes in folklore can possess a person of their own will, Kitsunetsuki is often attributed to the malign intents of hereditary fox employers, or tsukimono-suji.

Folklorist Lafcadio Hearn describes the condition in the first volume of his Glimpses of Unfamiliar Japan: