神田川
Nanboku incorporated two sensational and real-life murders into "Yotsuya Kaidan", combining fact and fiction in a manner that resonated with audiences. The first involved two servants who had murdered their respective masters. They were caught and executed on the same day. The second murder was from a samurai who discovered his concubine was having an affair with a servant. The samurai had the faithless concubine and servant nailed to a wooden board and thrown into the Kanda River.