These materials are the texts of reports and petitions written in the 16th and 17th centuries by four Jesuit missionaries in Japan, one of whom was Luis Frois, to the Jesuit headquarters and authorities. Discovered in Portugal (almost no Jesuit documents are known to have been retained in Japan), they were translated, reprinted with explanatory notes, and published in June 1987 to commemorate the 40th anniversary of the foundation of Kyoto University of Foreign Studies.