"Occultic;Nine" is a manga series adapted from the light novel of the same name, written by Chiyomaru Shikura. The story revolves around a group of nine individuals whose lives become intertwined through a series of mysterious and supernatural events. The narrative begins with Yuta Gamon, a high school student who runs a blog dedicated to occult phenomena. His blog, "Kirikiri Basara," garners attention from various individuals with their own connections to the occult.

The central plot is set in motion when Yuta and his friend Ryoka Narusawa, a part-time shrine maiden, encounter a series of bizarre incidents. These include the discovery of a corpse with a missing head and the sudden appearance of a mysterious girl named Sarai Hashigami, who claims to be a ghost. As Yuta delves deeper into these occurrences, he crosses paths with other key characters, each with their own unique backgrounds and motivations.

Among these characters are Miyuu Aikawa, a genius hacker with a penchant for conspiracy theories; Ririka Nishizono, a journalist investigating paranormal activities; Aria Kurenaino, a popular idol with a dark secret; and Touko Sumikaze, a scientist researching quantum mechanics. The group also includes Ryo-tas, a NEET with a deep interest in the occult; Shun Moritsuka, a self-proclaimed psychic; and Detective Shunpei Yasu, who is investigating the strange events surrounding the group.

As the story progresses, the characters uncover a larger conspiracy involving a secret organization known as the "Kisaragi Association," which is conducting experiments to manipulate reality and human consciousness. The narrative explores themes of quantum physics, parallel worlds, and the nature of existence, blending elements of science fiction with supernatural horror. The characters' fates become increasingly intertwined as they confront the truth behind the occult phenomena and the sinister forces at play.

The manga maintains a fast-paced and intricate plot, with multiple twists and revelations that keep the reader engaged. The interplay between the characters and their individual arcs adds depth to the story, while the exploration of complex scientific and philosophical concepts provides a thought-provoking backdrop. "Occultic;Nine" is a compelling blend of mystery, suspense, and the supernatural, offering a unique and immersive reading experience.