Inui no Kaze, as well as Hōsō (疱瘡), Ekishin, Anazi and Tamakaze, are all terms that are synonyms for smallpox. Until the advent of vaccination in the modern era, catching smallpox generally led to death. As the disease's sporadic outbreaks could decimae entire populations, smallpox was much feared in the past. The therm "inui" is based on the Chinese zodiac and it represents the direction of northwest.[1]