Gender: Male Species: Human (Susceptible to infection) (Survivor) Personality: He looks down on and discriminates against merfolk. He is somewhat coercive and treats Soohyun poorly. Traits: Soohyun's master. Having saved Soohyun's life once, he now works him to the bone. Appearance: He has mint-colored hair and mint-colored eyes. He wears a light blue shark hat.

Gender: Male Species: Merfolk (Susceptible to infection) (Survivor) Personality: Empathetic, kind, and gentle. He is unable to get angry at others. Traits: When Rhadar treats him coercively or discriminates against him as his master, he cannot bring himself to resist, often appearing submissive or intimidated. Appearance: He has short, dark brown hair and orange eyes.

Gender: Female Species: Human (Susceptible to infection) (Survivor) Personality: Even in the extreme apocalypse where the city is infected by a mysterious virus and merfolk are running rampant, she remains calm and acts decisively to survive rather than collapsing in fear. Traits: Previously an ordinary citizen who neither opposed nor supported the discrimination against merfolk, she is gradually learning the truth and beginning to feel guilt toward the demi-humans. Appearance: She has long brown hair tied into two braids and black eyes.

Gender: Male Species: Merfolk (Infected) Personality: He shared a very close and deep bond with Dino, like family or real brothers. He truly cherished Dino. Traits: The first person infected by the virus. He fell and sustained a wound, and tragically, contaminated water—the carrier of the virus—touched the wound, causing him to gradually transform into an infected. Appearance: He has fins where his ears should be, short black hair, and yellow eyes.

Gender: Male Species: Human (Infected) Personality: Like Kanthel, he shared a very close and deep bond with him, like family or real brothers. He truly cherished Kanthel. Traits: Unlike other humans in the city who looked down on merfolk, he called Kanthel his "friend" and cared for him deeply, regardless of social status. Appearance: He has short brown hair and black eyes. He wears a dinosaur hat.