Mikito Sakurai, a timid and bullied middle school student, struggles with feelings of inadequacy and a desire for strength. One night, he encounters a mysterious figure named Zakuro, who offers him the power to change his life. Mikito accepts, unaware of the consequences. He soon discovers that Zakuro has transformed him into a "mogari," a human with the ability to turn into a monstrous ogre. This transformation grants him immense physical strength but comes with a dangerous side effect: an insatiable hunger for human flesh. As Mikito grapples with his new reality, he learns that other mogari exist, each with their own struggles and motivations.

The narrative explores Mikito's internal conflict as he tries to maintain his humanity while resisting the monstrous urges that threaten to consume him. He forms an uneasy alliance with Zakuro, who serves as both a guide and a manipulative force, pushing Mikito to embrace his ogre nature. Along the way, Mikito encounters other mogari, including Mii, a young girl who has also been transformed, and Shizuka, a skilled fighter who seeks to protect humans from the dangers posed by ogres. These interactions reveal the complexities of the mogari existence, as some strive to coexist with humans while others succumb to their darker instincts.

The story delves into themes of identity, morality, and the struggle between human and monstrous impulses. Mikito's journey is marked by battles against other mogari, confrontations with humans who fear and hunt his kind, and moments of introspection as he questions what it means to be human. The tension escalates as Mikito learns more about the origins of the mogari and the true nature of Zakuro's intentions. The narrative builds toward a climactic confrontation that forces Mikito to make a definitive choice about his path and the kind of being he wishes to become.

The manga balances action-packed sequences with introspective moments, creating a compelling exploration of its central themes. Mikito's growth as a character is central to the story, as he evolves from a passive victim of circumstance to someone who actively shapes his destiny. The supporting cast, including Zakuro, Mii, and Shizuka, adds depth to the narrative, each representing different perspectives on the mogari condition. The series maintains a steady pace, blending supernatural elements with emotional stakes to create a cohesive and engaging story.