Millie Nocturne, whose full name is Millennium Feria Nocturne, is a young woman with short blonde hair and blue eyes. She originally worked as a detective at a private detective agency but was fired after becoming involved in an incident with Kane Blueriver during a mission against the criminal organization known as the Dugall Connection. She later becomes an unwilling partner of Kane and his shipboard computer, Canal, joining them on their space adventures. Millie is a happy-go-lucky and energetic individual whose catchphrase is her aspiration to be the best in the universe at any field she attempts. This drive leads her to try many roles, including detective, bounty hunter, sharpshooter, and even beauty pageant contestant, though she frequently fails to achieve her lofty goal. Despite her often comedic clumsiness, she is a highly skilled sharpshooter and an excellent cook, although her cooking frequently causes explosions that destroy kitchens. She also possesses basic detective skills, such as picking locks with a hairpin. Her personality is loud, emotional, and lively, creating a stark contrast with the more stoic and cool-headed Kane. She often engages in comedic arguments and fights with him, but their relationship is built on mutual support. Millie shows some jealousy toward Canal, particularly regarding Kane's attention. A major revelation in her story occurs late in the series when she discovers that her true family name is Stargazer and that she is a relative of Albert von Stargazer, the head of the Nightmare syndicate. Having never known her family, she is unaware of this until the clone of Stargazer, the Spreader of Darkness, summons her with the intent to make her kill Kane. Millie's role in the narrative serves as both comic relief and a proxy for the audience, as she is often the one who uncovers details about Kane's past and experiences emotional moments alongside him. Over the course of the series, she develops from a purely self-interested amateur into a loyal companion who stands by her friends in the final conflict. After Kane and Canal disappear, Millie is shown living in the home that once belonged to Kane and his grandmother, waiting for their return.