Departing for Onnakubi Station at 5 AM

(from ebookjapan):

Onna-no-kubi village...

the name comes from the fact that a long time ago, a wrongdoing woman was beheaded by the daimyo and her head was kept on a street in the village for a month....

In the Onna-no-kubi village, murders occur one after another between the rival Nitobe family and the Kukijo family.

Kazuya, the eldest son of the Nitobe family and a newspaper reporter, returns to his hometown to solve the mystery of the murders!