Two newcomers, Haru and Kai, begin their careers at Japan’s Narcotic Control Department. Together they confront drug dealers, gangs, murderers, psychopaths, shadowy organizations, and other dangerous individuals. Kai, the gentle and caring member of the team, carries personal troubles that occasionally transform him into a lethal killing machine. His behavior shifts dramatically like a switch. As the duo work side by side, the mysteries behind Kai’s strange conduct and his true identity gradually unfold.