"Stand My Heroes: Piece of Truth" is a crime drama anime centered around the Narcotics Control Department (NCD), a specialized unit tasked with combating drug-related crimes in Japan. The story primarily unfolds through the perspective of Rei Mizushima, a young woman who joins the NCD as a new recruit. Rei’s father, a former police officer, was falsely accused of drug trafficking and died under mysterious circumstances, fueling her determination to uncover the truth behind his death and clear his name.

The NCD is composed of a diverse team of agents, each with unique skills and backgrounds. Key members include Toshiyuki Sena, a calm and analytical leader; Shizuka Minase, a sharp and resourceful investigator; and Kujo, a former delinquent with a strong sense of justice. The team also includes Aoi Ichinose, a reserved but highly skilled agent, and Masaki Momose, a cheerful and empathetic officer. Together, they tackle various drug-related cases, ranging from street-level operations to high-profile investigations involving powerful criminal organizations.

As Rei integrates into the NCD, she becomes involved in a series of complex cases that gradually reveal connections to her father’s past. The narrative explores themes of justice, trust, and the moral ambiguities surrounding law enforcement and drug control. The team’s investigations often lead to confrontations with dangerous criminals, including members of the enigmatic drug syndicate known as "Adonis," which plays a central role in the overarching plot.

Throughout the series, Rei’s relationships with her colleagues deepen, and she gains their trust while uncovering critical information about her father’s case. The story balances episodic crime-solving with a larger, interconnected mystery, culminating in a confrontation with Adonis and the revelation of long-buried secrets. The anime combines elements of procedural drama, character-driven storytelling, and suspense, offering a grounded yet engaging exploration of the challenges faced by those working on the frontlines of drug enforcement.