central religious ceremony of Ainu culture was the sending-back ritual, in which the spirits of animals, plants, and implements were returned to the heavenly realm, the dwelling place of the ancestral spirits. ceremony comprises an expression of gratitude towards the spirits for the things they have bestowed upon mankind, and may be seen as a respectful return gift from humanity to the heavens. sendingback ritual thus exists within the context of a dualistic weltanschauung, comprised of the realm of the aynu (human beings)' on one side and the realm of the kamuy (spirits) on the other. Ainu, in the words of KITAKAMAE Tar6 (1985, p. 71), did not view humanity as the world's sole major constituent -existence was conceived of in terms of what might be called a balanced symbol model, composed of an interplay or reciprocal communication between aynu and kamuy. KITAKAMAE goes on to say, The term kamuy is often translated as 'god,' but what the concept really represents is a spiritual being that appears in the aynu world clad in the outer form of animals such as bears, owls, and salmon, plants such as monkshood, diseases such as smallpox, and natural phenomena such as fire and lightning (1985, p. 72). outer form of something is hence simply a disguise (hayokpe) adopted by the kamuy. Even smallpox is treated as a manifestation of the