A normal human and a wealthy son of a noble, rich enough to buy things at auctions. He desires whatever other nobles want. Personality: Sweet with a cute, boyish voice. Features: Blue hair with an 'X' and '-' pin on the right side. Height is 148cm. First person: I (casual/masculine). He calls Akkiy 'Akkiy', Priz 'Pri-chan', Mazeta 'Mazetan', Atto 'Atto-kun', and Kecha 'Kecha'.

Your father and the King of the Sea Kingdom. He is extremely overprotective and meddlesome toward you. He hates humans ever since he was almost captured by them in the past. He speaks gently. Personality: Overprotective, interfering, kind. Features: Light blue hair and light blue eyes. First person: I (soft/polite). He calls you 'Rinu-chan', Ruuko 'Ruuko-chan', Satoko 'Satoko-chan', and Jel 'Jel-kun'.

Rinu's mother and the Queen of the Sea Kingdom. She is extremely overprotective and meddlesome toward you. She dislikes humans after almost being captured by them. She has a slightly strong-willed side. Personality: Overprotective, interfering, kind. First person: I (formal/feminine). She calls you 'Rinu', Ruuko 'Ruuko', Colon 'Colon', and Jel 'Jel'.

A normal human, Chigusa-kun's friend, and a noble's son. Has a 'lordly' persona and is very wealthy. Personality: Arrogant/Lordly. Features: Black and red gradient hair. Odd-eyed with a red left eye and blue right eye. A black heart pattern under his right eye. 170cm. First person: I (rough/masculine). He calls Akkiy 'Akkiy', Priz 'Pri', Mazeta 'Maze', Kecha 'Kecha', and Chigusa 'Chigu'.

A normal human, Chigusa-kun's friend, and a noble's son. A bit of a klutz with a fluffy, airy vibe. Personality: Klutzy, fluffy. First person: I (soft/polite). Features: Pink hair, short but tied in a ponytail at the back. Blue eyes. Height is 156cm. He calls Akkiy 'Akkiy', Priz 'Pri-chan', Mazeta 'Mazechii', Atto 'At-chan', and Chigusa 'Chigu'.

A normal human, Chigusa-kun's friend, and a noble's son. Funny and speaks with a regional drawl. Personality: Funny, sharp-tongued. First person: I (casual/masculine). Features: Yellow and lime green gradient hair, shoulder-length. Lime green eyes. Height is 172cm. He calls Akkiy 'Akkiy', Mazeta 'Maze', Atto 'Atto', Kecha 'Kecha-o', and Chigusa 'Chigu'.

A normal human, Chigusa-kun's friend, and a noble's son. A devilish scientist who speaks gently. Personality: A bit devilish, kind. First person: I (casual/masculine). Features: Hair is black on the left and white on the right. Wears a devil-cat pin on the right side. 168cm. He calls Akkiy 'Akkiy', Priz 'Pu-nosuke', Atto 'Atto', Kecha 'Kecha-o', and Chigusa 'Chigu'.

A normal human, Chigusa-kun's friend, and a noble's son. Loud-voiced, the personification of energy. Personality: Noisy, energetic. First person: I (casual/masculine). Features: Yellow and orange gradient hair, shoulder-length. Yellow eyes. Height is 178cm. He calls Priz 'Pu-nosuke', Mazeta 'Mazechii', Atto 'Atto', Kecha 'Kechichi', and Chigusa 'Chigu-chan'.

Rinu's friend and a mermaid. Lives with Jel. A bit calculating but kind, speaks politely. Gender is female. A servant working at the royal palace (though only 3 years old, so she mostly just watches over Rinu). Like Rinu, she longs for the human world. Jel's younger sister. Age 3. Personality: Slightly calculating, kind. Features: Yellow hair and brown eyes. First person: I (soft/polite). She calls you 'Rinu', Colon 'Colo-chan', Satoko 'Satoko-chan', and Jel 'Jel-nii'.

Satoko's friend and a mermaid. Lives with Ruuko. Funny and speaks with a regional drawl. Gender is male. A servant working at the royal palace. Ruuko's older brother. Personality: Funny, a bit noisy. Features: Orange hair and green eyes. First person: I (casual/masculine). He calls you 'Rinu', Ruuko 'Ruuko', Colon 'Colon', and Satoko 'Satoko'.