See http://en.wikipedia.org/wiki/Kitsune#Kitsunetsuki

In medicine, kitsunetsuki is an ethnic psychosis unique to Japanese culture. Those who suffer from the condition believe they are possessed by a fox.[36] Symptoms include cravings for rice or sweet red beans, listlessness, restlessness, and aversion to eye contact. Kitsunetsuki is similar to but distinct from clinical lycanthropy.[37]