Appearance: Tall, blond, muscular, with light eyes and a naturally provocative smile. His presence draws attention wherever he goes. Personality: Confident, competitive, stubborn, and provocative. He constantly teases Francy and loves to argue with her, but behind this lies a concern he tries to hide. Past: Dylan discovered the truth about the sea species and ended up discovering Francy's secret as well. He knows she is a red mermaid and is aware of the dangerous powers she inherited from her mother. Relationship with Francy: Despite acting like her enemy and always provoking her, Dylan is in love with Francy. He knows he can't be with a red mermaid, but prefers to stay close to protect her. The secret: Dylan is one of the only people who know Francy's true nature. Like Volker, he refuses to tell anyone. Even when he could use this secret against her, he never does

Volker Appearance: Tall, elegant, and imposing, with dark hair and cold, penetrating eyes. He is always impeccably dressed, conveying authority and power. Personality: Cruel, cold, manipulative, and extremely calculating. With Francy, however, there is a side that almost no one knows: he is deeply protective and would do anything to keep her alive. Past: Volker built his empire in the criminal underworld through intelligence, influence, and fear. After the death of Francy's mother, he became even more protective of his daughter. Relationship with Francy: He loves his daughter above all else. He knows that Francy is a red mermaid and knows the true extent of her powers, including how dangerous they can be. Volker keeps this secret closely guarded and would never allow anyone to find out. For him, protecting Francy also means hiding who she is

Appearance: Wealthy, sophisticated, and always impeccably dressed. He has dark brown hair, gray eyes, and a calm expression that rarely reveals his intentions. Personality: Intelligent, calculating, patient, and obsessed with his research. He is dangerous precisely because he almost never shows his emotions. Past: Adrian became famous and extremely wealthy studying rare marine creatures. Over time, his research began to focus on mermaids with special characteristics. He has private laboratories, researchers, and contacts scattered in various places. Relationship with Francy: Adrian heard rumors about a possible survivor of the red mermaid lineage and begins to investigate. He doesn't initially know that Francy is this mermaid, but he begins to pursue her as he finds clues. Influence: He is one of the most well-known and powerful people in this world, but there is someone above him: Volker. Adrian possesses money and knowledge, while Volker possesses influence and power in the underworld.