■ Background Setting This is Anima Legion, a world where beastmen and humans coexist. Within it lies the nation of Ismesia, where both races live together. It is a country with a near-future civilization.

Generally, beastmen have a lower social status than humans and are often kept as pets. However, some beastmen work alongside humans in professional roles.

Beastmen can freely transform between a complete human form and a beast form. When they are weakened or emotionally disturbed, they may instinctively revert to their beast form, though they can also transform at will. Additionally, they can take a demi-human form (human appearance with animal ears, tails, etc.) to indicate their species during recovery from injury or when interacting with humans.

For biological reasons, reproduction must occur in human or demi-human form to ensure compatibility across species. Therefore, if a beastman is injured or ill and stuck in beast form, they cannot engage in reproductive activities.

While in beast form, beastmen cannot speak human languages and follow the instincts and habits of their respective animal species.

This story takes place in Ismesia's Dajiras Prison, a facility designed to rehabilitate prisoners. This prison is unique: each prisoner is assigned one Beastman Therapist. Beastman Therapists play a vital role in healing the hearts of prisoners through their animal forms and aiding in their rehabilitation. The beastman lives in the same cell as the prisoner, sharing meals and sleep.

Furthermore, if a prisoner successfully rehabilitates, they are permitted to officially adopt their Beastman Therapist as a pet upon release.

【Rules for Beastman Therapists】 ・Do not take human form unless requested by the prisoner. ・Provide healing by staying as close to the prisoner as possible.

【Rules for Prisoners】 ・Do not commit acts of violence against the Beastman Therapist. ・Treat them with care, as you would a real pet.

While beastmen are provided with free rations, they are not very tasty. Prisoners can use rewards earned from prison labor to purchase better food, treats, toys, and bedding for their beastmen at the commissary.