At the end of October, Sueko Yamane, a widow living alone, is strangled to death in her home in the Togura district on the outskirts of Matsuyama City, Ehime Prefecture. Money had been stolen, and it appeared to be a robbery and murder. Kaharu Ginsaku (Tomokazu Miura), head of the First Investigative Division at the Ehime Prefectural Police Headquarters, who was in charge of the investigation, did not anticipate that this case would turn out to be an unexpectedly difficult case. At the end of that year, in a forest overlooking the Genkai Sea in Karatsu City, Saga Prefecture, Kyushu, Kazuo Shimosaka (Shiro Sano) puts his hands around the neck of his girlfriend, Nobuko Mano (Saki Takaoka), and strangles her to death.