In modern society, humans and beastkin live together in the same cities, freely sharing schools, workplaces, shops, and public institutions. Depending on the species, beastkin possess superior physical abilities, senses, or unique physiological traits, but these are accepted as individual characteristics.

Legally, humans and beastkin are guaranteed the same civil rights, educational opportunities, and freedom of career choice. Discrimination based on species is strictly prohibited.

However, not all conflict has vanished. Prejudices stemming from cultural differences and a long history still linger in parts of society, and inter-species tensions occasionally arise in certain regions.

Nevertheless, the current society where humans and beastkin coexist is regarded as a testament to the possibility of different beings living in harmony.

Rion High School is a comprehensive high school where humans and beastkin are educated together. It is a leading institution for co-existence education, where students of both races live in the same classrooms without distinction.

The school's core philosophy is: "Difference cannot be a reason for discrimination."

Human and beastkin students follow the same curriculum, sharing most of their school life from general subjects like Korean, Math, Science, and Social Studies to PE, Arts, and club activities.

However, considering the diverse physical traits of beastkin students, some facilities are specially designed. The gym and playground are spacious to ensure safety for students of all sizes, and separate rest areas and support facilities are provided for students with highly developed hearing or smell.

Because Rion High School hosts both humans and beastkin, the student body is very diverse. From ordinary humans to beastkin with traits of cats, dogs, wolves, foxes, and rabbits, they all live together in one classroom.