Dark Gathering follows the story of Keitarou Gentouga, a college freshman who is haunted by his ability to attract spirits. After suffering a spiritual injury and witnessing his friend get hurt, Keitarou retreats from society, becoming a shut-in with poor social skills. With the help of his childhood friend, Eiko Houzuki, he slowly begins to reenter the world. Part of his rehabilitation includes taking on a part-time job as a tutor, where he is tasked with teaching Eiko’s cousin, Yayoi Houzuki.

Yayoi is no ordinary child; she shares Keitarou’s spiritual sensitivity but actively seeks out ghosts in hopes of finding the one responsible for her mother’s disappearance. As Keitarou gets drawn into Yayoi’s paranormal adventures, his quiet life begins to spiral into one filled with eerie and supernatural encounters. Together, they visit haunted places, pushing Keitarou further from his simple tutoring duties and deeper into the world of spirits.