The National Local Mascot Festival provides a chance for kids to interact with beloved mascots from different regions of Japan. However, as the event kicks off, a sinister truth unfolds - the individuals inside these costumes are not human but something far more ominous, craving human flesh. In the midst of the ensuing nationwide turmoil, Keigo Ayahara, his younger brother Makoto, and their friend Ako find themselves in a fight for survival and the preservation of their own humanity.