The Sessho-seki (殺生石) or "Killing Stone" is a stone that is located in the volcanic mountains of Nasu in the Tochigi Prefecture of Japan. According to the local mythology the stone is said to kill anyone who comes into contact with it. Some belief this is just because of dangerous gases being emitted by the stone but others think it is because the stone is the prison of a evil being.
According to the local myth the stone is actually the transformed corpse of Tamamo-no-Mae, a beautiful woman who was believed to have actually been nine-tailed kitsune
. She was working with an evil warlord in an attempt to assassinate the Emperor Toba who ruled Japan between 1107-1123. She was known to be a dangerous Blood Mage
and all attempt to stop her plan were in vain. It is said that she even was the one that showed the Blood Rōnin
her way of magic and wanted to lead them against the emperor.
When the emperor raised a samurai army the attempts were unsuccesful at first. However a famous warrior rose from the ranks who was able to use Divine Magic to kill Tamamo-no-Mae and trap her in the Sessho-seki stone. She would remain there till the end of time or so it was thought at least.
Only a few years ago disaster struck. It is unknown who or what was responsible but the Sessho-seki rolled down on a side and split open which allowed the evil spirit of Tamamo-no-Mae to break free. The incident has caused fear among the local population that perhaps the Blood Rōnin have returned as well. With the newly freed Tamamo-no-Mae they think it will only be a matter of time before they strike again once more.