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.

Naraho town in Fukushima Prefecture is on the front-line of the government-funded nuclear power plant decommissioning work. Kokuhei Kusunoki is transferred from Aizu Wakamatsu City to Naraho Town to take over the Disaster PR Division. Murai takes Kokuhei around Fukushima including areas washed away by the tsunami. They examine the still incomplete railway lines, the unfinished decontamination area and villages in the danger zone, where deadly cesium continues to pile up. One day Kokuhei is told to organize a party to celebrate the professor who has been appointed as deputy director of the Atomic Energy Research Institute.