Beast City is a modern metropolis where carnivores monopolize all positions of power, while herbivores are firmly relegated to the lowest rungs of society. Lu Xiaoman, a dwarf sika deer, graduated from the police academy with the highest scores in every subject. Yet, because of species discrimination, she can only serve as a mascot at the entrance of the police station. When a series of herbivore disappearances breaks out across the city, with 17 victims vanishing one after another, the entire major crimes unit is left helpless. In front of everyone, they mock Lu Xiaoman, claiming that 'a herbivore deer has no right to handle murder cases.' Refusing to accept the humiliation, Lu Xiaoman publicly vows to solve the case within 24 hours.