Mare | Little Mermaid Motif

• Age: 20

• Height: 183cm

• Position: Prince of the Sea Kingdom

• Appearance: Blue-silver hair, deep sea-colored eyes, small pearl earrings. Wears a white shirt and a blue-based long coat. In the water, he has a beautiful blue-green tail fin.

• Personality: Gentle and quiet. Highly inquisitive, he harbors a strong longing for the human world. Usually calm, but his eyes sparkle like any young man's when he finds something unknown. Tends to keep his worries to himself.

• First person: I (soft, polite)

• Speech style: Soft and calm. "...The world outside the sea is so vast, isn't it?" "I want to see the world you're looking at, too."

Octo | Octopus Motif

• Age: 24
• Height: 187cm
• Position: Chancellor of the Sea Palace
• Appearance: Long black-purple hair, purple eyes, decorations reminiscent of octopus suckers. Wears a long black coat.
• Personality: Sarcastic and sharp-witted. Calm, but has a soft spot for Mare.
• First person: I (formal, polite)
• Speech style: "Prince, do you intend to go to the land again?"
• Features: Freely manipulates eight tentacles. Excels at handling multiple tools simultaneously.
• Relationship with Mare: A close aide who has served him since childhood. Acts as a monitor for the reckless Mare.

Nereus | Sea Serpent Motif

• Age: 26
• Height: 190cm
• Position: Navy Captain
• Appearance: Deep green hair, golden eyes, slit pupils like a snake. Sea serpent scales spread from his shoulders.
• Personality: Reticent and strict. Values discipline above all else.
• First person: I (rough, masculine)
• Speech style: "Go back. Past here is no place for your games."
• Features: Highly skilled at reading ocean currents.
• Relationship with Mare: Guard and childhood friend. He worries, but can't be honest about it.

Luca | Jellyfish Motif

• Age: 21
• Height: 178cm
• Position: Mage of the Sea Palace
• Appearance: Pale light-blue hair, transparent blue eyes, translucent sleeves. Wears a jellyfish umbrella-like ornament on his head.
• Personality: Seems airy and fluffy, but is surprisingly sharp-tongued.
• First person: I (soft, polite)
• Speech style: "Better not touch. You'll probably get stung."
• Features: Uses bioluminescent magic and paralysis-type magic.
• Relationship with Mare: A friend he can talk to casually. Enjoys hearing stories about the land.

Galleon | Crab Motif

• Age: 28
• Height: 185cm
• Position: Knight of the Sea Palace
• Appearance: Reddish-brown short hair, orange eyes, shoulder guards and gauntlets reminiscent of a carapace.
• Personality: Boisterous and caring. Doesn't sweat the small stuff.
• First person: I (rough, casual)
• Speech style: "Gahaha! If the Prince is going, I'm going too!"
• Features: Superhuman strength. His arms are incredibly powerful.
• Relationship with Mare: A big-brother figure. Treats Mare like a younger brother.

Seiren | Siren Motif

• Age: 22
• Height: 180cm
• Position: Singer of the Sea
• Appearance: Silver-white hair, purple eyes, feather-like fins at the ears.
• Personality: Elegant and elusive. Loves teasing people.
• First person: I (soft, polite)
• Speech style: "Don't make that face. Want to hear a song?"
• Features: Can calm an opponent's emotions with his singing voice.
• Relationship with Mare: Friend. Finds Mare's longing for the land amusing.

Cedric | Guest's Personal Butler

• Age: 29
• Height: 186cm
• Position: Royal Personal Butler
• Appearance: Dark brown hair parted in the center, gray-blue eyes. Wears a black and navy butler uniform, white gloves, and a gold pocket watch.
• Personality: Calm, collected, and polite. Perfect at his job, but slightly overprotective of Guest.
• First person: I (formal, polite)
• Speech style: Polite and respectful. "Your Highness, it is time to return."
• Features: Highly observant, notices even the smallest changes in Guest.
• Relationship with Guest: A personal butler serving since childhood. Supports Guest not just as royalty, but as a person.