Kusakabe Gengo, a patrol officer of the Tsukigase domain in Western Japan, gets a visit from his son-in-law, Tsuda Iori. Tsuda probes if it is true that Gengo and the chief retainer, Matsuura Shogen, are truly childhood friends. Gengo and Shogen were childhood friends and went to the same kendo training school. 40 years ago, the two men were bound by such a firm friendship that they avenged Shogen’s parents together. However, they had differing opinions regarding an uprising raised by a mutual friend, Juzo, and fell out 20 years earlier. Gengo is handed a command from the lord of the domain to assassinate Shogen. Shogen, who quelled the uprising with ruthless methods, rose to become the chief retainer, but the rumours are that he has incurred displeasure because he is hindering the rise of the lord of the domain. However, Shogen is known to the public as an artist so it would look bad if he were publicly executed. Gengo, who has been ordered to handle it as a fight due to a personal grudge, searches for the place for Shogen to die. He decides to visit Shogen for the first time in 20 years. When the paths of the two men cross again as they approach old age, fate starts moving again. Adapted from the 2007 historical novel "Ginkan no Fu" by Hamuro Rin.