A man frustrated by lost wages is reluctantly recruited by the Monster Purification Bureau as an Intern Investigator, offering a low base salary but high commission for defeating monsters. Though he initially rejects training and doubts the job, he commits to the bureau, hoping to get rich quickly with his special abilities. After hours without any action, he finally receives his first assignment: investigate a forest where brutal attacks on women are rumored, though others dismiss these as ghost stories. Despite warnings, he pushes forward, driven by money, setting the stage for a dangerous confrontation.