Maeno Ryotaku (Kataoka Ainosuke) is a doctor of Buzen Province, Nakatsu domain. Aspiring to learn Western knowledge, he comes across a Dutch-language translation of the German medical text Anatomische Tabellen while studying in Nagasaki. After returning from Nagasaki, Maeno is invited by a doctor friend Sugita Genpaku (Niiro Shinya) of Wakasa Province, Obama domain to observe an autopsy.

The background to and depiction of a watershed battle in Japanese history, at Sekigahara in 1600, when Tokugawa Ieyasu's Army of the East defeated the Army of the West of Ishida Mitsunari. The story includes the intrigues and shifting loyalties of the various retainers, family members, and samurai.