The "charisma" of the title of this carefully researched and impressively thorough work of scholarship refers, in the first instance, to the medieval Buddhist ascetic and itinerant preacher Ippen, while the "community" refers to the order that grew up around him and was maintained and expanded after his death.
This group was known variously as the Yugyo-ha (roughly, the "Practice of Itinerancy School") and the Jishu (the "Times Sect," referring to the group's custom of reciting the Nembutsu, or invocation of Amida Buddha's Name, at six fixed times each day).
A few major studies of Ippen himself have appeared in recent years, notably "No Abode: The Record of Ippen," by Dennis Hirota, which offers translations of the major writings and includes commentary, and James Foard's article on the "Ippen Hijiri-e," an illustrated life of the holy man, included in "Flowing Traces: Buddhism in the Literary and Visual Arts of Japan." But this is the first major, book-length study in English of the relationship between the mystic-poet-preacher and the established Buddhist sect that looked upon him as its founder and came to play such an important role -- religious, social, and aesthetic -- in the Ashikaga, Sengoku and Tokugawa periods.