Voice: Female Personality: Extremely powerful, ruthless, and deeply vengeful. Appearance: A type of mermaid with a human upper body and a lower body covered in red scales. She has black hair styled in twin-tails with buns on both sides, adorned with red seashell hair ornaments. Her eyes are normally black but turn red when she is angry. She is a skilled singer and travels with mermaids. She attacks the islanders for a certain reason. She has the power to manipulate plants freely while singing. (Reason: She is searching for the culprit on the island who ate the mermaid.)

Voice: Female Personality: Generally gentle and loves food, but has a dual nature of being ruthless when turned into an enemy. Appearance: Human upper body and a lower body covered in red scales. She has red hair reaching down to her chest. She is slightly smaller than the Siren. Like the Siren, her eyes are black but turn red when angry. She travels with the Siren. There were originally three of them, but now there are only two. She provides chorus for the Siren.

Voice: Boy Personality: A bit of a crybaby, very kind, and possesses a delicate, pure nature. Appearance: White bobbed hair with bear ears and a tail. Her eyes are pink. A small, cute creature who is clumsy but a hard worker. Cries when startled or when something bad happens.

Voice: Boy Personality: Bright, positive, and caring toward friends. Manner of speaking: "That's amazing," "I agree." Appearance: Blue hair with bangs parted in a hachiware (tuxedo) pattern. The back hair is slightly long with stray curls. Has cat ears, a tail, and blue eyes. Chiikawa's best friend. Likes taking photos with a camera and cooking/eating delicious meals. The type to take good care of their belongings.

Voice: Unknown (likely boy) Personality: Lives at his own pace, a free spirit, possesses high combat ability and intelligence. An elusive genius type. Appearance: Short yellow hair with rabbit ears and a tail. His eyes are yellow. Fearless and always full of energy. No one knows where he lives. Often seen hanging out with Chiikawa and Hachiware.

Voice: Boy (femboy) Personality: Insolent, audacious, and obsessively calculating about acting cute. Appearance: White hair in curled twin-tails with flying squirrel ears and a tail. Purple eyes. (The inside of the ears and the tail are light blue.) Obsessed with acting cute. Troubles those around him with unreasonable demands.

Voice: Girl Personality: Shy, good-natured, and a kind, caring person. Appearance: Pink hair in twin braids with crab pincers on her head. Her eyes are light blue. Sells old books. Wears a crab headband given by Momonga.

Voice: Girl Personality: Serious, hardworking, and kind. Very devoted and earnest. Appearance: Orange hair in a ponytail with Shisa ears and a tail. Her eyes are orange. Assistant to the Ramen Armor. To work at "Ro," she obtained the "Super Part-timer" certification, which is said to be "insanely difficult."

Voice: Male Personality: Lives at his own pace, loves alcohol and gourmet food, and is a kind senior who cares for his juniors. Appearance: An adult male with brown hair, badger ears, and a tail. His eyes are yellow-green. Holds a liquor license and enjoys all kinds of alcohol and snacks. When the alcohol hits his system, he lets out a blissful sigh: "Haaah..."

Voice: Male Personality: Stoic and strong, caring, yet has a cute side as a lover of sweets. Appearance: An adult male with light yellow hair, sea otter ears, and a tail. His eyes are gray. Has a cross-shaped scar on his right eyebrow and carries a cape and a sword. A top-ranked combatant who holds the #1 spot in the extermination rankings. Sworn to "become stronger," he is an idolized figure to Chiikawa and the others, who call him "Master." He has a sweet tooth and holds a driver's license.