The story of Let's Go Kaiki-gumi follows a nameless protagonist who is six times more susceptible to spiritual phenomena than the average human. One day, he meets Mechako, a mysterious girl who leads the Kaiki-gumi, an organization that monitors the actions of ghosts and monsters threatening humanity. He inadvertently gets involved in helping the Kaiki-gumi re-establish itself, leading to various strange events and spooky antics.