"Maetel Legend" is a two-episode OVA that serves as a prequel to the broader "Galaxy Express 999" universe, exploring the origins of Maetel, one of the franchise's central characters. The story is set on the planet La Metal, a dystopian world ruled by the tyrannical Queen Promethium. The planet's inhabitants are oppressed, forced into labor, and stripped of their humanity, with many transformed into mechanical beings to serve the queen's ambitions of eternal rule. Maetel, the queen's daughter, initially appears loyal to her mother but harbors deep internal conflict about the suffering inflicted on her people.

The narrative begins with Maetel's return to La Metal after a prolonged absence. She reunites with her childhood friend, Emeraldes, who has become a resistance fighter against Queen Promethium's regime. Emeraldes reveals the extent of the queen's cruelty, including the exploitation of La Metal's citizens and the destruction of their free will. Maetel, torn between her familial duty and her growing empathy for the oppressed, begins to question her mother's actions. Her internal struggle intensifies as she witnesses firsthand the suffering of the people and the resistance's desperate efforts to overthrow the queen.

Queen Promethium, aware of Maetel's wavering loyalty, attempts to manipulate her daughter into embracing her vision of a mechanized, immortal empire. However, Maetel's encounters with the resistance and her deepening bond with Emeraldes lead her to reject her mother's ideology. The climax of the story revolves around Maetel's decision to confront Queen Promethium, culminating in a dramatic showdown that forces her to choose between her bloodline and her moral convictions. This pivotal moment sets the stage for Maetel's future role as a symbol of hope and resistance in the "Galaxy Express 999" saga.

The OVA delves into themes of oppression, rebellion, and the struggle for identity, with Maetel's journey serving as the emotional core of the narrative. Her transformation from a seemingly compliant princess to a defiant figurehead for liberation underscores the series' exploration of personal and societal redemption. The supporting characters, particularly Emeraldes and Queen Promethium, provide contrasting perspectives on power and justice, enriching the story's moral complexity. "Maetel Legend" stands as a compelling origin story that deepens the lore of the "Galaxy Express 999" universe while offering a self-contained tale of resistance and self-discovery.