The evolutionary importance of religion is a topic of considerable debate in recent scholarship. This article reassesses Neil Gordon Munro's ethnography of the Ainu people in Hokkaido area focusing attention on the Chisei Nomi ceremony. Munro describes kamui (ancestor spirits), who take part in the Chisei Nomi as active, observant, non-living persons. The ritual acts in the Chisei Nomi ceremony are reinterpreted using recent theoretical perspectives of perspectivism and evolutionary-communication theory. The Chisei Nomi promotes a healthy environment for close kin by establishing respect for long deceased ancestors.