"Beasts of Abigaile" is a supernatural romance manga set in a fictional European island nation called Ruberia. The story centers on Nina, a cheerful and determined teenage girl who is unexpectedly bitten by a mysterious wolf-like creature while visiting Ruberia. This bite transforms her into a werewolf, leading to her capture and imprisonment in Abigaile, a prison-like academy for werewolves located on a remote island. The werewolves, referred to as "beasts," are segregated from human society and live under strict surveillance.

Abigaile is divided into hierarchical factions based on the color of the roses each werewolf wears, symbolizing their rank and strength. The red roses represent the most powerful and elite, while the blue roses denote the weakest. Nina, initially marked with a blue rose, struggles to adapt to the harsh and competitive environment of the academy. Her human origins make her an outsider, and she faces prejudice and hostility from other students. However, her resilience and unique perspective begin to challenge the rigid social structure of Abigaile.

Nina’s interactions with the other students drive much of the narrative. Roy, a brooding and powerful red rose werewolf, becomes a central figure in her life. Despite his aloof demeanor, Roy is drawn to Nina’s determination and kindness, and their relationship evolves into a complex dynamic of trust and rivalry. Other key characters include Gilles, a blue rose werewolf who befriends Nina, and the enigmatic headmaster, who oversees the academy with a hidden agenda. The story explores themes of identity, discrimination, and the struggle for freedom as Nina navigates her new reality and uncovers the secrets of Abigaile.

The plot delves into the political and social tensions within the academy, as well as the broader conflict between humans and werewolves. Nina’s presence disrupts the status quo, sparking rebellion and challenging the oppressive systems that govern the lives of the beasts. As she grows stronger and gains allies, Nina becomes a symbol of hope for those seeking to break free from their chains. The narrative balances action, romance, and intrigue, with a focus on Nina’s journey of self-discovery and her efforts to bridge the divide between humans and werewolves.