Reddit mentions of The Practice of Concern: Ritual, Well-Being, and Aging in Rural Japan (Carolina Academic Press Ethnographic Studies in Medical Anth)

This is important. It should also be noted that Japan is an interesting case study in the belief vs. practice aspect of religious expression.

While Japanese people may identify as non-religious in belief, they still participate in certain rites that most would classify as imbued with a certain religious power (concern, to borrow from Paul Tillich).

John Traphagan's The Practice of Concern is a pretty involved study of this dichotomy in Japan.