Sesshō-seki and Tamamo no Mae

The Sesshō-seki (Japanese: 殺生石), or "Killing Stone," is an object in Japanese mythology.

It is said that the stone kills anyone who comes into contact with it.

The stone is believed to be the transformed corpse of Tamamo no Mae, a beautiful woman who was exposed to be a nine-tailed fox working for an evil daimyo plotting to kill the Japanese Emperor Konoe and take his throne.

Stories of Tamamo-no-Mae were written and collected in the Otogizōshi of the Muromachi period, and were also mentioned by Toriyama Sekien in Konjaku Hyakki Shūi. Tamamo-no-Mae was a courtesan under the Japanese Emperor Konoe. She was said to be a most beautiful and intelligent woman in Japan. She caused the Emperor to be extremely ill and was chased away by Abe no Yasuchika, who had been called to diagnose the cause of the Emperor's poor health. Abe no Yasuchika discovered the true nature of Tamamo-no-mae. A few years later, in the area of Nasu, the nine-tailed fox was seen killing and eating women and travelers. Emperor Konoe thus sent Kazusa-no-suke and Miura-no-suke along with 80,000 troops to kill the fox. In the plains of Nasu, it was finally killed and became a stone called the sesshoseki. The stone continually released poisonous gas, killing everything that touched it. The stone was said to have been destroyed in the Nanboku-chō period by Gennoh Shinshou, and the pieces flew away to different parts of Japan. 

As told in the Otogizōshi, when the nine-tailed fox was killed by the famous warrior Miura-nosuke (he killed the magical creature with an arrow), its body became the Sesshō-seki.

The Sessho-seki was said to be haunted by Hoji, the transformed spirit of the nine-tailed fox, until a Buddhist priest called Genno stopped for a rest near the stone, and was threatened by Hoji. Genno performed certain spiritual rituals, and begged the spirit to consider her spiritual salvation, until finally Hoji relented and swore to never haunt the stone again.

In Matsuo Bashō's famous book, The Narrow Road to the Deep North (Oku no Hosomichi), Bashō tells of visiting the stone in Nasu, located in modern-day Tochigi Prefecture. Today, an area in the volcanic mountains of Nasu (famous for their sulfur hot springs) commemorates the myth.