"Shanghai Dragon" is an anime series set in a fictionalized version of 1930s Shanghai, blending historical elements with supernatural and martial arts themes. The narrative centers on Long Fei, a young martial artist who becomes entangled in a conflict between powerful factions vying for control of the city. Long Fei, initially a street performer with a mysterious past, discovers he is the reincarnation of an ancient dragon spirit, granting him extraordinary abilities. This revelation draws the attention of both allies and enemies, including the enigmatic Black Lotus Society, a secretive organization seeking to harness his power for their own ambitions.

The plot unfolds as Long Fei navigates the treacherous underworld of Shanghai, encountering a diverse cast of characters. Among them is Mei Ling, a skilled assassin with her own hidden agenda, who forms a complex alliance with Long Fei. Their relationship evolves amidst the chaos, as they confront rival gangs, corrupt officials, and supernatural entities. The series also introduces Zhang Wei, a former military officer turned vigilante, who becomes a mentor figure to Long Fei, guiding him in mastering his newfound abilities while uncovering the truth about his lineage.

As the story progresses, Long Fei learns of an ancient prophecy foretelling the rise of a dragon who will either save or destroy Shanghai. This prophecy becomes the focal point of the conflict, with various factions attempting to manipulate Long Fei to fulfill their own destinies. The narrative delves into themes of identity, loyalty, and the struggle between fate and free will, as Long Fei grapples with his role in the prophecy and the moral dilemmas it presents.

The series is marked by its intricate world-building, blending historical Shanghai with fantastical elements such as mythical creatures, ancient artifacts, and mystical martial arts techniques. The action sequences are a key feature, showcasing a mix of traditional Chinese martial arts and supernatural combat. The interplay between the characters' personal journeys and the larger political and supernatural conflicts drives the narrative forward, culminating in a climactic battle that determines the fate of Shanghai and its inhabitants.