In Showa 31 (1956), Nagura Village was secretly controlled by the Ryuga family, who dominated Japan's political and financial circles. Mizuki, who worked at the Imperial Blood Bank, entered the village under the pretense of mourning the death of the head of the family, carrying ambitions and a secret mission. At the same time, Kitaro's father entered the village searching for his wife. Within the Ryuga family, a vicious struggle over succession had begun.

(Source: Toei Animation)