Dark Gathering follows Keitaro Gentoga, a university student cursed with a strong connection to spirits after a traumatic supernatural incident in his childhood. Trying to move on with his life, he becomes a tutor for Yayoi Hozuki, a mysterious young girl obsessed with capturing dangerous ghosts to find the spirit that took her mother. Together with Eiko, they explore haunted places and confront terrifying supernatural entities in a dark journey filled with horror, mystery, and psychological tension.