Sesshō-seki volcanic lava and legend at Nasu Town

Sesshō-seki (殺生石) is a lump of volcanic lava that sits near Nasu Yumoto Onsen in Nasu Town, Nasu District, Tochigi Prefecture. The site is long known for ongoing emissions of volcanic gases; historically those gases have been blamed for the sudden deaths of birds and other animals, which is how the rock took on the name that evokes “taking life.” The stone and its immediate surroundings are today treated as a named scenic place and receive many visitors, though entry can be regulated when gas emissions increase.

First impressions and the site today

The rock is part of a small, managed area commonly called the Sesshō-seki garden area. Visitors approach a conspicuous lava formation that has been tied to local legend and to volcanic activity. The site is described as a place where volcanic gases such as hydrogen sulfide and sulfurous gas are emitted continuously across the immediate vicinity; because of that, authorities post warnings and sometimes restrict access when emission levels are high. The garden-area designation and the presence of interpretive signs have made the spot a well-known local attraction.

Volcanic gases and recorded incidents

The floating gases named in local descriptions are hydrogen sulfide and “sulfurous” gas; these emissions have long been associated with animal mortality near the stone. The modern record includes a number of incidents: carcasses of foxes and raccoon dogs (tanuki) have been found in the area over the years, and on 7 December 2022 eight wild boar carcasses (three adults and five juveniles) were discovered lying near the right-rear side of the Sesshō-seki area, where gas emergence is believed to be heavier. Those carcasses were collected the next day by staff from the Ministry of the Environment and Nasu Town and were incinerated. Signage at the site specifically cautions that while the gases are not a problem for people who stay away from the immediate vents, care is advised for visitors with infants or pets.

Recent changes to the stone

On 5 March 2022 the main Sesshō-seki formation was confirmed to have split into two. Staff had observed cracks on the rock for several years before the break, and Nasu Town reported that it judged a natural fracture to be the most likely cause. The event was significant for local residents; at the end of March the Nasu Town Tourism Association held a memorial and peace-prayer ritual near the stone.

Literary and official recognition

Sesshō-seki has an established place in Japanese literary and cultural history: the haiku poet Matsuo Bashō visited the site during the journey recorded as Oku no Hosomichi and wrote about it in that travel account. At the national level, the site has been designated a Place of Scenic Beauty by the government; the designation date is 18 March 2014.

The Tamamo-no-Mae and Nine‑Tailed Fox legend

Local folklore links the stone to the famous Tamamo‑no‑Mae story. In that tradition, Tamamo‑no‑Mae—described as a woman who was favored by Emperor Toba—was actually a nine‑tailed fox in disguise. The fox was exposed by an onmyōji named Abe and fled to the eastern provinces, where it was pursued by three warriors given in the tradition as Kazusa-no-suke Hirotsune, Chiba-no-suke Tsunetane and Miura-no-suke Yoshizumi. The fox is said to have been driven into a stone that thereafter emitted a poisonous vapour and continued to kill living creatures; the stone became known as the “killing stone.” The legend further records that in Jitoku 2 (1385) a monk named Gen’ō struck the stone and shattered it, and fragments were said to have been scattered across Japan.

Those fragments are linked in various local traditions to several places called “Takada” around the country. Candidates named in the tradition (given as historic provinces and their modern equivalents) include Takada in Mimasaka (now Katsuyama, Maniwa City in Okayama Prefecture), Takada in Echigo (now Jōetsu City in Niigata Prefecture), Takada in Aki (now Akitakata City in Hiroshima Prefecture), Takada in Bungo (now Bungotakada City in Ōita Prefecture), and Takada in Aizu (now Aizu Misato Town in Fukushima Prefecture). Other regional versions of the story say fragments became a burdock seed in Hida, an inugami (dog spirit) in Shikoku, or an osaki spirit in the old province of Kōzuke.

Related places and cultural echoes

Several shrines and temples across Japan claim associations with Sesshō-seki in the form of a stone, shrine or relic said to derive from the original. Examples named in those local traditions include Kaseiji in Katsuyama (Maniwa City, Okayama), where a stone mound connected to the Sesshō-seki story stands within the temple grounds; Isasumi Shrine in Aizu Misato Town, which maintains a small Sesshō-seki Inari shrine and, on that basis, has developed an official exchange relationship with Nasu Town (exchanges began in 2008 and a friendship agreement was signed in 2015); Jōzaiin in Shirakawa, which keeps a piece said to be from the stone together with a seated statue of Gen’ō and a painted picture-scroll recounting the monk’s deeds; and Shinnyo‑dō in Kyoto, where a statue called the Kamakura Jizō is traditionally said to have been made from a fragment. A different Sesshō-seki site in Kokonoe (Kusu District, Ōita Prefecture) appears in a separate local legend and likewise was once described as emitting poisonous gas that caused animal deaths.

Gojinka Festival (sacred-fire ritual)

Each May the Nasu Town Tourism Association stages a ritual known as the Gojinka Festival to pray for the pacification of the active volcano Chausu (part of the Nasu range). The festival features a torch procession of about 100 participants dressed in white with fox masks and face paint; they light a ceremonial fire at Nasu Onsen Shrine called the “Mugen Jigoku” fire and bring it down to the Sesshō-seki area. After the ritual, a roughly five‑metre-tall ceremonial torch called the Gojinka is ignited near the stone, and a drum performance titled the White-Faced Golden Nine‑Tailed Fox Taiko is presented. In 2022 the festival’s flame was also used as part of the torch for the Ichigo Ichie Tochigi National Sports Festival.

FAQ

What is Sesshō-seki?

Sesshō-seki is a lava rock near Nasu Yumoto Onsen in Nasu Town, Nasu District, Tochigi Prefecture.

Why is it called "killing stone"?

The rock and its vicinity emit volcanic gases such as hydrogen sulfide and sulfurous gas that have long been known to kill birds and other animals.

When did the national designation occur?

Sesshō-seki was designated a national Place of Scenic Beauty on 18 March 2014.

Has the stone ever been damaged in modern times?

On 5 March 2022 the stone was confirmed to have split into two; a crack had been observed years earlier and local authorities judged a natural break likely.