"Harmony" is a manga adaptation of the science fiction novel by Project Itoh, illustrated by Range Murata and written by Tetsuya Tsutsui. The story is set in a future where society has achieved a state of near-perfect health and stability through a system called "Harmony," which monitors and regulates human behavior to prevent conflict and disease. This utopian system is maintained by advanced nanotechnology and a global network known as the "WatchMe" system, which ensures compliance by suppressing harmful emotions and actions.

The protagonist, Tuan Kirie, lives in this controlled world where individuality and personal freedom are sacrificed for collective well-being. Tuan is a survivor of a failed mass suicide attempt orchestrated by her childhood friend, Miach Mihie, who sought to rebel against the oppressive system. Years after the incident, Tuan works as a "Helix Inspector," tasked with investigating anomalies in the Harmony system. When a series of mysterious deaths occur, Tuan is drawn into a deeper investigation that challenges her understanding of the world and her own identity.

As Tuan delves into the case, she uncovers unsettling truths about the Harmony system and its creators. The narrative explores themes of autonomy, the cost of utopia, and the ethical implications of sacrificing individuality for societal stability. Tuan's journey forces her to confront her past, her relationship with Miach, and the moral ambiguities of the system she once accepted without question. The story builds toward a climactic revelation about the true nature of Harmony and the extent of human agency within it.

The manga retains the philosophical depth and dystopian tone of the original novel, presenting a thought-provoking exploration of a world where perfection comes at a profound cost. The characters, particularly Tuan and Miach, are central to the narrative, with their contrasting perspectives on freedom and control driving the story's emotional and intellectual tension. The artwork by Range Murata complements the futuristic setting, blending detailed, atmospheric visuals with a sense of unease that underscores the story's themes.