The Oni-Gara
Professor Asanuma leads a team of six folklorists, both men and women, searching for a site known as the Demon Shell Stone. Ignoring villagers' warnings, they climb a mountain in a village for investigation. However, upon discovering the Demon Shell Stone at the summit, one member suddenly goes mad, attacks, and devours Professor Asanuma. They attempt to descend immediately, but the cannibalism seems contagious; members rapidly lose their sanity.
Similar films
Made in Abyss: Dawn of the Deep Soul
Demon Slayer -Kimetsu no Yaiba- The Movie: Mugen Train
Onibaba
They Reach
Demon Slayer: Kimetsu no Yaiba -To the Hashira Training-
Dragon Ball Z: Wrath of the Dragon
Whistle
Death Note: The Last Name
Demon Slayer: Kimetsu no Yaiba Mt. Natagumo Arc
As Above, So Below
Deathgasm
Bleach the Movie: Hell Verse