This thesis is the history of the latter half of Zeami's life, and the tragic story of his secret papers, with which he initiated his successors into the secret. The tragical events, in succession, have come from the conflicts among three elements as follows, (1) the personal patronage of three persons of the Ashikaga Shognate, Yoshimitsu, Yoshimochi and Yoshinori, (2) Zeami's individual authority on the No-drama, (3) the tradition of initiating sons and pupils into the secret. In his last years, his second son entered the priesthood, the eldest son died early death in his thirties, his grand son was left as a child, his company nearly collapsed, and he himself, at the age of seventy-two, was exiled on the northern solitary island, Sado-gashima. In the latter half of his life, however, Zeami had left secret papers, about twenty volumes in number, which were what you would call his will. These secret papers have kept alive to this day during six hundred years since his death.