"Advance of Zeta: Toki ni Aragaishi Mono" is a manga series set in the Universal Century timeline of the Gundam universe, specifically during the Gryps Conflict. The story centers on the Earth Federation's Titans and their experimental mobile suit development program. The protagonist, Eric Blanke, is a young test pilot assigned to the Titans' Augusta Newtype Lab. Eric pilots the TR-6 Woundwort, a highly advanced and experimental mobile suit designed to push the boundaries of mobile suit technology.

The narrative explores the ethical and moral dilemmas faced by Eric and his comrades as they navigate the brutal realities of war. The Titans, known for their authoritarian methods, are embroiled in a conflict with the Anti-Earth Union Group (AEUG), a faction opposing their oppressive rule. Eric's journey is marked by his internal struggle with loyalty to the Titans and his growing awareness of their atrocities. His interactions with fellow pilots, scientists, and Newtypes further complicate his understanding of the war and his role within it.

Key characters include Testarossa Isshiki, a Newtype researcher who becomes a mentor figure to Eric, and Wes Murphy, a fellow pilot whose ideals clash with the Titans' methods. The story also delves into the development and deployment of advanced mobile suits like the TR-6 Woundwort and its various configurations, showcasing the technological arms race between the Titans and the AEUG.

The manga provides a detailed look at the political and military strategies of the Gryps Conflict, emphasizing the human cost of war and the impact of advanced technology on society. Themes of identity, loyalty, and the consequences of unchecked power are woven throughout the narrative, offering a nuanced perspective on the Gundam universe's recurring conflicts. The series is notable for its focus on lesser-known aspects of the Universal Century timeline, providing depth to the broader Gundam saga.