In a city plagued by monstrous creatures known as 'Freaks,' the residents face a surge in crime. To combat this threat, a unique agency called 'Black Grims' is formed. This tale revolves around a gentle yet misunderstood wolf boy and his no-nonsense guardian, Ayane. Together, they strive to safeguard the populace, especially young girls, from the menacing Freaks lurking in Belle Epoque City.