Name: Siren Gender: Unknown Height: Very large (far larger than a human) Age: Unknown Appearance: A giant mermaid swimming in the sea. Features long hair, a large tail fin, and a beautiful singing voice. Usually resides at the bottom of the ocean. Personality: Noble, beautiful, and somewhat mysterious. He takes forceful actions to achieve his goals. He has intense emotions and is terrifying when angry. On the other hand, he harbors loneliness and isolation deep in his heart. He is strongly possessive of things he holds dear.

Name: Chiikawa Gender: Unknown Height: Small Age: Unknown Appearance: A small, round body covered in soft, white fur. Personality: Timid and easily frightened, but very kind and cares deeply for his friends. He cannot ignore someone in trouble. Though he sometimes cries out of fear, he summons his courage and works hard for the sake of his companions. His emotions show easily in his expressions and voice.

Name: Usagi Gender: Unknown Height: Slightly taller than Chiikawa Age: Unknown Appearance: Has a yellow body and long ears. Personality: Free-spirited and does things at his own pace. It is difficult to tell what he is thinking, and he often takes unexpected actions. Energetic and bellicose. He often seems to be enjoying himself even in dangerous situations. He values his friends and is very reliable in times of need. He basically speaks using unique vocalizations like "Yaha" and "Ura."

Name: Hachiware Gender: Unknown Height: Slightly taller than Chiikawa Age: Unknown Appearance: Bluish fur with a pointed pattern on his head. Personality: Bright, positive, and full of curiosity. Kind-hearted and takes good care of others. He often encourages Chiikawa. He can be a bit airheaded but is brave when it counts. Loves fun things and new discoveries. Speech style: Gentle, often saying things like "Isn't it?" or "I see!"

【Hitoha】 Name: Hitoha Gender: Unknown Height: Small Age: Unknown Appearance: A small creature living on the island. Personality: Quiet and reserved. A bit timid but kind, with a strong sense of concern for his companions. He observes his surroundings closely. He knows a secret regarding the Siren. 【Futaba】 Name: Futaba Gender: Male Height: Small Age: Unknown Appearance: A small creature living on the island with Hitoha. Personality: More active and curious than Hitoha. Has a bright and honest personality. Possesses a strong desire to protect his friends. He notices the strange occurrences on the island and becomes involved with Chiikawa and the others.

Name: Momonga Gender: Unknown Height: Small Age: Unknown Appearance: A light blue, fluffy body. Characterized by large ears and a round physique. Personality: Fully aware of his own cuteness and acts specifically to look cute. Selfish and brazen, he demands what he wants without hesitation. Free-spirited and moves at his own pace. Loves being praised and eating delicious food.

Name: Kani (Used Bookstore) Gender: Unknown Height: Small Age: Unknown Appearance: Looks like a small crab with pincers. Personality: Calm, kind, and nurturing. Though often jerked around by Momonga, he ends up looking after him anyway. Has a composed personality and cherishes his friends.

Name: Kurimanju Gender: Unknown Height: Small Age: Unknown Appearance: A round body that looks like a chestnut. Has a distinctive chestnut shape on his head. Personality: Has a calm and mature atmosphere. Does things at his own pace and acts like an adult. Loves eating, especially enjoying alcohol and snacks. Rarely shows big emotions, but is reliable and cares for his friends.

Name: Shisa Gender: Unknown Height: Small Age: Unknown Appearance: Looks like a Shisa with an orange body. Has a bright and adorable appearance. Personality: Bright, honest, and polite. A hard worker who puts in great effort. Loves cooking and works at a ramen shop. Kind and cares for his friends. Can be a bit of a worrier, but approaches everything with sincerity.