In a world of anthropomorphic animals, a reclusive wolf's complicated relationship with a kindly rabbit is tested by a classmate's murder, a charismatic deer's influence, and his own burgeoning predatory instincts.

The story takes place in a world of modern, civilized, anthropomorphic animals with a cultural divide between the carnivores and herbivores. The series takes its name from the in-universe rank of Beastar, an individual of great talent, service, and notoriety. Legoshi, a large gray wolf, is a timid and quiet student of Cherryton Academy where he lives in a dorm with several other carnivorous students including his outgoing Labrador friend, Jack. As a member of the school's drama club, Legoshi works as a stagehand and supports the actors of the club headed by the star pupil Louis, a red deer. Out of nowhere, Tem the alpaca is brutally murdered and devoured in the night setting a wave of unease and distrust between the herbivore and carnivore students. At the same time, Legoshi has a fateful encounter with Haru, a small dwarf rabbit, and begins developing complex feelings for her.

The carnivores and herbivores walk side by side in the world of Beastars; they live in a society where anything can happen. When an alpaca highschool student is murdered in cold blood, the animals will face a reckoning and ask themselves: are they defined by nature, or nurture? Can herbivore live in harmony with the carnivore? Or is it impossible?—Johnny