Mt. Kokureishin (Mt. Koku/The Snow Mountain) is a large mountain in Hokkan and lies North of Touran. Its peak hides the shrine of Genbu's Shinzaho, guarded by the spirits of Celestial Warriors, Hikitsu and Tomite.
Genbu Kaiden Arc
Takiko first appears on Mt. Koku when she is first pulled into the world of the book. At the time, an ancient stone pillar stood on the mountain top but monsters lurked underneath the snow. Because of this, a village nearby made it a tradition to chain criminals to the pillar and they would either succumb to the cold or to the monsters. The Celestial Warrior, Uruki, is initially sentenced to die on the peak and he is barely kept alive by his celestial powers before Takiko appears and saves him.
When Hikitsu and Tomite meet their end during the Summoning Ceremony at the Battle of Touran, Taiitsukun guides their spirits to Mt. Koku and constructs a sacred shrine to house Takiko's Shinzaho, a jeweled necklace. Hikitsu and Tomite both vow to protect the shrine in honor of their priestess.
Fushigi Yuugi Arc
Over 200 years after Takiko first appeared atop the mountain, the Celestial Warriors of Suzaku fail to summon Suzaku and venture into Hokkan to retrieve the Shinzaho. The pillar Uruki was once chained to has deteriorated and lost in the ice and snow. The shrine remains, albeit, frozen shut and blocked by a bolder. It is here where Celestial Warrior, Nuriko, dies defending the peak from Ashitare of the Seiryuu Seven. He uses the last of his strength to remove the heavy bolder from the entryway and is buried by his friends on the snowy summit.
The rest of the Suzaku Seven enter the shrine, deeply saddened by the loss of their friend, and meet the spirits of Hikitsu and Tomite, who put Miaka, the Priestess of Suzaku, through a test of strength to see if she is worthy of taking Takiko's Shinzaho. When she passes, the two Genbu Warriors' spirits are able to rest, having fulfilled their duty, and join Takiko and the other warriors in the afterlife.