Gruier Serenity is a key character in the anime series Mōretsu Pirates. She is the first princess of the Serenity Kingdom, a powerful and influential monarchy within the universe of the series. Gruier is characterized by her regal demeanor, intelligence, and strong sense of responsibility. She seeks the help of the protagonist, Marika Kato, to solve a mysterious issue involving the Serenity Royal Family. Gruier's role is pivotal as her actions and decisions significantly influence the plot, showcasing her growth from a sheltered princess to a decisive leader.