Mokume is a first-year university student and a passionate occult fanatic. Determined to experience supernatural phenomena firsthand, she transfers to a specific university because of a rumored older student named Kugutsu, who is said to attract urban legends like a magnet. She finds the university's Occult Club nearly abandoned and its president elusive, but she eventually tracks down Kugutsu and convinces him to let her join, striking a deal to accompany him on his bizarre adventures. The setting is a contemporary Japanese university campus and various real-world locations where urban legends are said to manifest, from dark city streets to remote villages and lakes.

Kugutsu is the story's reluctant core. He possesses an unwanted ability that draws all kinds of supernatural entities toward him, and he simply wishes to live a peaceful, legend-free life. Mokume is his energetic and fearless counterpart, a girl who actively seeks out the very monsters Kugutsu tries to avoid. The Occult Club members form an eclectic supporting cast: a girl with long black hair who resembles the ghost Sadako and has a hobby of nailing straw dolls to trees, a club president who looks like a child despite her age and is obsessed with cryptids, and a tall, athletic-looking boy who seems more suited for a sports club. Their dynamic blends genuine horror with comedic banter as they are forced to work together.

The series follows an episodic yet interconnected structure, with the club investigating a different urban legend or cryptid in each storyline. Their first major encounter is with Kuchisake-onna, the masked woman who asks if she is pretty. The meeting turns into a chaotic chase where the group must use quick thinking and a clever answer to survive. Subsequent arcs involve the Charlie Game, a mysterious man who appears in dreams; a high-speed chase with Turbo Granny, forcing the athletes of the group to keep up with a speeding car; a trip to a lake to hunt for the Loch Ness Monster, which reveals the complicated feelings of a crew member whose father faked sightings for a tourism program; and a journey to a remote village called Woof-Woof Village, where the gang is drugged and captured to be sacrificed to the dog god Inugami. Another notable arc involves a search for a human-faced dog, blending local folklore with disturbing revelations. While many supernatural threats are real, some investigations uncover human deception, though Kugutsu's presence often ensures that something genuine and dangerous eventually appears. The narrative balances moments of genuine creepiness with irreverent humor, and the club members gradually grow closer as they face increasingly perilous situations together.