Genisyu was a military epic written in the late period of the Northern and Southern Courts (Japan) (in the latter half of the 14th century). 'Genji no i' (The Power of Genji), that is, the book's main contents were the rightness of Kawachi-Genji's (the Minamoto clan's) military rule (during the Kamakura period and of the Muromachi government) and the stories of Togoku Samurai warriors who supported the military rule. Naomitsu YUKI and Moroyoshi SATAKE are believed to be the two possible authors. The book comes in two volumes.
The original copy existing today was written by Mitsumoto MAKABE (Jindayu) who was a descendant of Ujimoto MAKABE during the Genroku era in order to compile the history of the Akita domain and submitted to the head of Satake clan, the lord of the domain (Senshu Library owns the copy at present); therefore, the manuscripts stored at the Historiographical Institute at the University of Tokyo and books published today all originate with the original copy.
The book is written in a format that a retired old army general told stories of Genji and the history of Togoku Samurai by answering his grandchild's and great-grandchild's questions. The book starts with the story of Genji and Hachiman Daibosatsu's relationship, and moves on to the stories of the historical episode of MINAMOTO no Yoshimitsu's flute during Zen Kunen no Eki (the Early Nine Years' War) and Gosannen no Eki (the Later Three Years' War), the exposure of MINAMOTO no Yoshichika's severed head, the domination over FUJIWARA no Yasuhira, MINAMOTO no Yoritomo's two attempts to conquer the capital (Kyoto) and Takauji ASHIKAGA's attempt to conquer the capital and the battle of Toji Temple.
Describing Genji's ties to the leaders of samurai families and Togoku Samurai were emphasized; therefore, events not related directly to Togoku (the eastern part of Japan, particularly Kanto region) such as the Hogen War, the Heiji War, and the Genpei War were omitted. Also, Genisyu describes in detail the emerging customs of samurai families at the time and is valued as the accumulation of records before the books on the ancient practices of customs of samurai families were compiled.