I once spent a couple of years in a few communities which could be described as 'alternative' or 'utopian' (to a greater or lesser degree) - mainly Schloß Elmau and Atarashiki-mura, although I did also stay at 'Milky Way' in Mitaka (Tokyo) and visit Bakugenjin-mura (獏原人村) in Fukushima and Myoga-mura (茗荷村) in Shiga. For those interested in this general area I'd recommend Utopia Britannica and a rare book called "The Communes of Japan: The Kibbutz on the Other Side of the World" by Zenzo Kusakari, Michael M. Steinbach and Moshe Matsuba, published in 1977 by Imaichi Nihon Kyodotai Kyokai. The Encyclopedia of Community also looks interesting, although I've not read it.