He worked on writing a full-length history book called 'Chuko Nihon Chiranki' (literally, the History of Peace and War of medieval Japan) which was commissioned by Hideyoshi TOYOTOMI because Hideyoshi wanted a book sequel to Taiheiki (The Record of the Great Peace).
秀吉の命により太平記の続書として長編歴史書「中古日本治乱記」を執筆。