A solitary man named Sakichi once discovered a strange demon infant abandoned in the mountains. He decided to raise the child as his own, giving him the name Aka. After the young demon grew up, he returned to his natural habitat in the wilderness, yet Sakichi found he could never erase the bond from his memory. Years later, Sakichi ventures back into the mountains in search of Aka, only to find that the child he raised has become a fully grown adult demon, a creature of the forest now regarded as a monster. Despite the impossibility of a relationship between a human and a demon, an undeniable attraction draws them together. As they succumb to this passion, they set in motion a tragic series of events that will ultimately stain the pure white snow with blood.

The story is structured as a short, self-contained tale divided into several chapters, with the first serving as an introduction to the characters and their world. After this setup, the narrative focuses almost entirely on the isolated dynamic between the man and the demon alone in the woods, where the passage of time becomes a central element. The core of the plot revolves around the difficulties of their connection, particularly the barrier of language, as Aka does not understand human speech. This forces the two to communicate through gestures, expressions, and physical intimacy rather than conversation, creating a poetic and sensory-driven reading experience. The artwork is noted for its ethereal and detailed style, effectively conveying the oppressive solitude of the forest and the contrasting beauty and violence of their relationship.

Sakichi is portrayed as a lonely human outcast, whose isolation from human society is a key aspect of his character. His decision to raise a demon baby stems from this deep-seated solitude, and his later actions are driven by a complex mix of longing and desperation. Aka is the demon child who grows into a mysterious and powerful forest creature. His motivations are often ambiguous due to his lack of speech, making him an enigmatic presence driven largely by instinct and emotion. The story explores a controversial relationship dynamic, as the bond shifts from a paternal figure caring for a child to a romantic and physical relationship with the adult demon, a transition that some readers may find uncomfortable.

The setting is a remote, seemingly timeless forest and the isolated mountains, far removed from any village. This location acts as a physical and metaphorical space for the characters solitude, with the changing seasons and the encroaching snow reflecting the emotional state of the protagonists. The manga is divided into narrative arcs that begin with the initial discovery and childhood of Aka. This is followed by a lengthy separation and the pivotal reunion between Sakichi and the adult Aka. The final arc focuses on the deepening of their physical and emotional relationship and the tragic consequences that inevitably follow, leading to a conclusion described as both beautiful and disturbing.