This is a voluminous book written by Dogen, the founder of the Nihon Sotoshu sect (Sotoshu sect in Japan), over a large period of his life, from 1231 to his death in 1253, which consists of eighty-seven volumes (seventy-five volumes, plus a further twelve volumes), and includes the essence of the philosophy of the Nihon Sotoshu sect.
日本曹洞宗の開祖である道元が、1231年から示寂する1253年まで生涯をかけて著した87巻（＝75巻＋12巻）に及ぶ大著であり、日本曹洞禅思想の神髄が説かれている。