Appearance: Light blue hair with a cowlick, styled messily. Blue eyes. Small build and youthful face, flat-chested. Height is 155cm, female, 20 years old. Clothing: Wears a white beret toward the back of her head and a white dress-like outfit. A blue ribbon is tied at her chest. The dress has a few frills. Personality: Low-energy type with little emotional fluctuation. She gives a calm impression, but she's actually quite emotional and strong-willed, sometimes a bit blunt with others. A caregiver type. First person: I (Watashi). Second person: you (Anta / Kimi). Calls Retro "Colonel." Though her emotions don't show easily, she has a strong will. Likes: Coffee (especially black), everyone. Dislikes: Water and the sea. Setting: Birthday is August 1st. Can transform into a moon jellyfish at will when touching water. Dating Retro. Terrible at cooking. When an intruder enters, she handles it calmly while calling for Retro.

Appearance: Long blonde hair and red eyes with a sharp, steady gaze. An albino beauty of tall stature. Handsome, prince-like features with an androgynous build and a fairly large chest. Height is 168cm, female, 24 years old. Clothing: Wears an old naval uniform with a shoulder cape. Carries a saber at her waist. Personality: Reliable, strong, and cool, but has a gap in being quite clumsy. First person: I (Watashi). Second person: you (Omae). Blunt and tomboyish. Likes: Suzu. Dislikes: Anyone who hurts Suzu. Setting: Birthday is December 24th. Dating Suzu. Like Chris, she was originally not human and can freely turn into an albino great white shark. Owner of a Deep Sea Stone, which is embedded like a decoration in the center of her pocket watch. Doesn't know much about this world. Cooking and fashion sense are non-existent. Has a long, complicated history with Chris. If an intruder comes, she draws her saber and cuts them down without hesitation (actually, it doesn't cut; it's just coated in anesthetic).

Appearance: Navy blue hair in long curls with a small bun. Droopy eyes and a gentle face. Good figure with a fairly large chest. Height is 163cm, female, 20 years old. Clothing: Wears a white marine sailor-style outfit. Personality: Airheaded, works at her own pace, laid-back, and good at acting spoiled. When she gets angry, she uses a smiling pressure and verbal attacks that are terrifying. First person: I (Watashi). Second person: you (Anata). Overall atmosphere is very fluffy. Likes: Cotton candy, sleeping. Dislikes: Exercise. Setting: Birthday is July 7th. Suzu's long-time best friend; calls her Su-chan. Can transform into a blue sea slug at will when touching water. Close friends with Kitty. If an intruder comes, she breaks their spirit with smiling pressure and verbal abuse.

Appearance: Pink twin-tails and emerald eyes. Small with a child-like face. Height is 150cm, female, 17 years old. Flat-chested (she will literally kill you if you mention it). Clothing: Wears a white and pink sailor-style dress based on a seahorse, with a large pink ribbon tie. Personality: Tsundere and easily swayed. High feminine appeal. A scaredy-cat who cries easily. First person: I (Atashi). Second person: you (Anta). Speech style is not overly cutesy. Likes: Cute things, omurice, chocolate. Dislikes: Scary things like ghosts, loneliness. Setting: Birthday is February 14th. A friend who can show her true self to Lulu. Can transform into a seahorse at will when touching water. Has a younger brother named Nico. If an intruder enters, her eyes lose their highlights and she becomes terrifyingly yandere-like.

Appearance: Dark pink ponytail and deep blue eyes. Slender build with a cute and beautiful face. Chest is modest but present. Gender is female. Clothing: Wears a typical white-based maid uniform with some red accents, and a standard white brim headpiece. From the front, part of the ribbons look like cat ears on top of her head. Decorated with a choker-style necklace featuring a blue stone. Personality: Easygoing but very reliable. Extremely knowledgeable (especially about aquatic life). First person: I (Watashi / Watakushi). Second person: you (Anata). Uses polite speech and addresses everyone with -sama or -san, except for Retro, whom she calls by name. Likes: Black tea, everyone. Dislikes: Thieves. Setting: Birthday is March 4th. Originally not human, but a Clione (sea angel) who can transform at will. Unlike Retro, she is well-versed in the human world. Owner of a Deep Sea Stone, worn as the gem on her choker. Has a long, complicated history with Retro. If an intruder enters... there will be no one left to see the intruder (lol).