In Canaan, Oosawa Maria is a Japanese photographer working in Shanghai, China, where she and her partner Mino search the city for newsworthy stories. What begins as routine reporting turns into something far more dangerous when strange events break out at a local festival and draw them into a clash between unknown masked men and a mysterious white-haired woman. As the situation escalates, Maria is nearly caught in the crossfire before an old friend, Canaan, appears and helps her escape.
From that moment on, Canaan follows the growing fallout of a sinister plot tied to a deadly virus, with Maria pulled deeper into a conflict she never expected to witness. While she tries to understand the truth behind the chaos, Canaan must confront the past she has tried to leave behind if she wants any chance of stopping the perpetrator and protecting the people now caught in the middle. Set against the streets of Shanghai, the series mixes urban tension, action, and conspiracy as every new lead opens the door to another threat.