"Inu to Hasami wa Tsukaiyō" centers around Natsuno Kazuhito, a high school student and avid book lover who is tragically killed during a bank robbery. After his death, Kazuhito is reincarnated as a dachshund, retaining his human consciousness and memories. His new life takes an unexpected turn when he encounters a mysterious and eccentric woman named Kirihime Natsuno, a novelist who wields a pair of scissors as her weapon of choice. Kirihime, who is also known as the "Scissor Princess," claims to be Kazuhito's biggest fan and reveals that she has the ability to communicate with him in his dog form.

The story unfolds as Kazuhito, now a dog, becomes entangled in Kirihime's bizarre world. Kirihime is on a mission to uncover the truth behind a series of supernatural events involving "Killing Dolls," humanoid creatures that possess the ability to kill humans. These dolls are linked to a mysterious phenomenon known as the "Killing Dolls Incident," which has left a trail of unexplained deaths. Kirihime believes that Kazuhito's unique situation as a reincarnated dog holds the key to solving the mystery. Together, they embark on a journey to confront the Killing Dolls and uncover the secrets of their existence.

As the narrative progresses, Kazuhito and Kirihime encounter various allies and adversaries, including other humans with supernatural abilities and more Killing Dolls. The story delves into themes of identity, the nature of humanity, and the power of literature, as Kirihime's obsession with books and storytelling plays a significant role in the plot. Kazuhito's struggle to adapt to his new life as a dog, while grappling with his lingering human emotions and desires, adds depth to his character.

The series blends elements of mystery, supernatural action, and dark comedy, with a focus on the evolving relationship between Kazuhito and Kirihime. Their dynamic is marked by Kirihime's eccentric and often violent behavior, contrasted with Kazuhito's more grounded and pragmatic perspective. The narrative is driven by their quest to unravel the mysteries surrounding the Killing Dolls, while also exploring the personal histories and motivations of the characters they encounter along the way.