Even fantasy worlds aren't safe from the threat of invasive species!? Rokuroku of the Department of Countermeasures for Invasive Magical Creatures is tasked with investigating these beings alongside Ninin, a newly assigned and overly energetic elf girl. Rokuroku can barely keep up with her enthusiasm... Slimes, carbuncles, gargoyles—together, they work to protect and rescue various magical creatures! The Department of Countermeasures for Invasive Magical Creatures sets out once again today!