Lucia is the typical shoujo heroine: ditzy and lovestruck, but with a pure heart and a sense of love for her friends.
In the manga, she was raised to believe that she was a normal mermaid civilian, and lived on the surface as a human with her guardians, "sister" Nikora and "pet" Hippo (who is a penguin).
In the anime, she's always known that she is the Princess of the North Pacific Ocean, Pink Pearl Voice. Great, right... except for the "pink pearl" bit.
The pearl that gives her her power and is directly tied to her life force is gone; she gave it to a little boy to save his life when they were six. She gets it back from the boy, who turns out to be her classmate and crush Kaito, and realizes that she has to find the other ocean princesses and save the world. She's also expressly forbidden to confess her love or true identity to Kaito, but she's certain that she won't turn to foam if she finds some loophole. Little does she know that nobody turns to foam when they confess anyway...
Tropes associated with Lucia:
- Awesome Moment of Crowning: End of the manga.
- Changeling Fantasy: Manga only.
- Covert Pervert: Not as much as Hanon, though.
- Cute Clumsy Girl: Lucia trips over things all the time.
- Dangerous Thirteenth Birthday: Of course, Lucia's always known she's a mermaid, but in the manga she didn't find out she was a Mermaid Princess until her 13th birthday.
- Fear of Thunder: Possessed this trait.
- Genki Girl: Easily the most energetic and positive character in the series.
- Girlish Pigtails: Lucia has ditz/magical girl pigtails.
- G-Rated Drug: She gets drunk off cola in the manga.
- Hair Decorations: Wears two red ribbons while in human form.
- Hair Intakes: Her hairstyle has two intakes that kinda look like cat ears.
- Hair of Gold, Heart of Gold: She's blonde in mermaid form, in the anime, and in many manga pictures (it's very inconsistent), and she's a cute, kind and innocent princess.
- Heart Symbol: Cheesy hearts appear when Lucia performs her "Love Shower Pitch".
- Heroes Want Redheads: The manga's inconsistent colouring means that sometimes her boyfriend is the redhead, and sometimes she is.
- Idiot Hair: She has a cowlick that stands prominently atop her head. This is reflective of her ditzy personality.
- Image Song: "Koi wa Nandarou" ("What is Love?") and "Splash Dream." In the second season, "Mother Symphony" may also count.
- Interspecies Romance: a pink Mermaid Princess who loves Kaito since her childhood.
- "I Want" Song: "Koi wa Nandarou" and "Splash Dream".
- Kissing Under the Influence: Literally in the manga, Bowdlerised in the anime to be the result of a magic jewel.
- Locked Out of the Loop: Twice, but it doesn't make it past the second chapter of an arc.
- Love Triangle: Lucia-Kaito-Michal.
- Meaningful Name: Lucia is Latin for 'light', and Nanami is Japanese for 'seven seas'.
- Nonstandard Character Design: Weird case with her being the main character and it's quite subtle. While the other mermaids have Curtains Match the Window which match their tail does she have Hair of Gold, Heart of Gold with Innocent Blue Eyes.
- No Pronunciation Guide: Her name Lucia is actually pronounced "Luchia", which leads to translations having that spelling of her name.
- Pink Heroine: Her tail as a mermaid is pink, and her idol form outfit consists of a pink dress, pink gloves, and pink boots.
- Princesses Prefer Pink: Her tail and shell-bikini as a mermaid are pink, and her idol outfits are entirely pink as well.
- Rags to Royalty: She's a Sleeping Beauty in the manga and a Snow White in the anime.
- Rescue Romance: Lucia saved Kaito when they were children and they've remembered each other ever since. In the manga's final bonus chapter, it turns out that he also saved her at the same time when she was struggling to keep him afloat.
- Say It with Hearts: Not as often as Hanon, but a lot, including her "Love Shower Pitch."
- Say My Name: KAITOOOOOOOOOOOOOOOO!
- Town Girls: The Neither to Hanon's Femme and Rina's Butch.
- Trademark Favorite Food: A mermaid who actually eats seafood, for once.
- Two First Names: Nanami is a fairly common girls' name, and Lucia is her actual first name.
Hanon is a flirty, carefree, all-around girly-girl that befriends Lucia on her first day of school. She's more serious than she looks, however, and has been watching Lucia for days and confronts her with her true identity at the end of the first chapter. Hanon is actually the Princess of the South Atlantic Ocean, otherwise known as Aquamarine Pearl Voice. With her strength and happy nature, she makes a great first ally for Lucia, even though they're always at each other's throats — in particular, Hanon doesn't approve of Lucia dating Kaito at first, even though she's all over a human man, who, at that, happens to be her own teacher. Again, though, despite her peppy, fluffy, hypocritical image, Hanon feels tremendous guilt for the fate of her kingdom, which was besieged with her as the only apparent survivor.
Tropes associated with Hanon:
- As You Know: Hanon and Nicola like to go on about the rules of the mermaid world. Lucia usually actually doesn't know this. She's just that dense (or overprotected).
- The Chick: "Flirty, carefree, all-around girly-girl"
- Covert Pervert: Hanon is a hormonal teenager, all right.
- Declaration of Protection: What "Ever Blue" is about; protecting the ocean, your loved ones, etc.
- Doomed Hometown: Like most of the others, she fled a ruined homeland.
- First Kiss: Something she's dreamt about for ages.
- First-Name Basis: Hanon thrusts it upon everyone she meets.
- Hot for Teacher: Her first crush being Tarou Mitsuki.
- Image Song: "Ever Blue" and "Mizuiro no Senritsu" ("The Aquamarine Melody").
- I Want My Beloved to Be Happy: Eventually decides this despite how much it hurts her for Tarou to be in love with someone else.
- The Lancer: She likes disagreeing with Lucia.
- Quirky Household: Once Hanon moves in, the Shinju-yu/Pearl Piari becomes this instantly.
- Satellite Love Interest: She tends to go for guys who she just thinks are cute. Tarou is one of these; as crushed as she is to learn that he's interested in people his own age, she eventually gets over it when he leaves.
- Say It with Hearts: Every other sentence.
- There Is Another: A lot of Hanon's subjects did survive.
- Tomboy and Girly Girl: She's the girly one to Rina.
- Town Girls: The Femme to Lucia's Neither and Rina's Butch.
- Tsundere: Towards Nagisa. Since he's not her usual type, she tries her best to ignore that he's there.
- You Gotta Have Blue Hair: Most people in the show, actually, but Hanon deserves a mention for literal blue hair.
The standoffish transfer student that Lucia decides to befriend on a whim, Rina is idolized by her classmates as "cool" because she spends most of her time brooding and making the occasional sarcastic remark. She, too, is a princess: Green Pearl Voice from the North Atlantic Ocean. Rina acts as an emotional pillar for her friends, but she herself has issues that need to be dealt with. Even more so than Hanon, she carries a measure of guilt about her escape; after being forced to leave their countries behind, Rina and her friend, Princess Noel from the Arctic Ocean, were ambushed by Gackto and only Rina got away. Despite what she thinks of herself for this, she's a strong and loyal friend of her team.
Tropes associated with Rina:
- All Love Is Unrequited: Her crush on Kaito in the anime.
- Aloof Ally: Didn't last long.
- Bifauxnen: You couldn't tell by looking at her, but apparently, she is. She wears the boys' uniform, and Lucia and Hanon's first reaction to seeing her in the anime is "That was a girl... right?".
- Boke and Tsukkomi Routine: Rina wants to be a comedian in the anime. In one episode and its preview, she manages a decent routine with Lanhua.
- The Comically Serious: Particularly in the anime, where she's still serious but has things added to her character like being obsessed with plasma TVs and wanting to be a comedian.
- Custom Uniform: Rina wears the boys' uniform for no apparent reason.
- Don't Say Such Stupid Things: On both the giving and receiving ends.
- Doomed Hometown: She fled her home like many of the others when Gackt came along.
- Fun T-Shirt: Her "It's cool" shirt with the penguin on it.
- He Is Not My Boyfriend: Denies having anything going on with Hamasaki for ages.
- Hero with Bad Publicity: Gets this from Caren and the rest of the Antarctic Ocean during the first season. While Noel in fact sacrificed herself to give her a chance to escape from Gaito, Caren's kingdom believes that Rina abandoned Noel to save her own hide.
- Hime Cut: Fits with her status as a miko.
- Image Song: "Star Jewel" and "Piece of Love."
- Laying On A Hillside: Rina does this a lot in the anime, especially in Pure, when they had to reuse animation all the time and thus shots and whole chunks of scenes were repeated.
- Miko: In the manga, she works for a shrine to a spirit both mermaids and humans venerate.
- Mysterious Watcher: For one episode, before she turns out to be a Mermaid Princess herself.
- New Transfer Student: Apparently has a lot of rumours about her when she shows up, though we don't actually hear any.
- Non Action Song: "Piece Of Love" from Pure.
- Otaku: In the anime, she's given such an obsession with plasma TVs.
- Rapunzel Hair: In both forms.
- Tomboy and Girly Girl: She's the tomboy.
- Town Girls: The Butch to Lucia's Neither and Hanon's Femme.
- Tsundere: Type B for Masahiro.
- You Gotta Have Green Hair
Brash, bitter and initially unkind, Caren, otherwise known as Purple Pearl Voice and the Princess of the Antarctic Ocean, shows up mid-way through the first arc to rescue Lucia and company a few times. That doesn't, as she makes clear, mean that she plans to join them or become their friend. Caren is the fraternal twin sister of Noel, and as such, has a deep personal grudge against Rina for escaping when the other princess did not. She takes it upon herself to rescue her sister alone, and only when her brazen attempt gets her captured and the heroes rescue her but Noel sacrifices herself again does Caren realize that Rina wasn't selfish at all. She never quite integrates herself into the team for good, leaving more than once after the job's done, but is important enough to be listed with the main cast for the second half of the first arc/season.
Tropes associated with Caren:
- Aloof Ally: In her first appearances, Caren frequently saves Lucia and co. from danger, but is not at all interested in being friendly or hang out with them.
- Beauty Mark: Under her left eye.
- Big Eater: She's known to eat large amounts of food... and stick others with the bill.
- Broken Bird: Hearing that her sister was captured and believing that Rina left her for dead drive Caren to be very cynical.
- Dark Horse Victory: Her introduction in the anime.
- Does Not Like Men: One scanslation had her say this in her introduction. Other translations, including the official one, had her say "I have no interest in little boys", implying that it was the age of her hanger-on that made her dismiss him, not his gender. She later muses that love would be pointless anyway no matter who she was with, so whichever way she swings is up to reader discretion. In the anime, she does like men, but that has no bearing on the manga.
- Can't Catch Up: Come the Michel arc, she's not nearly as powerful as the main trio, especially in the anime.
- Deadpan Snarker: She's always got a wry comment to spare.
- Demoted to Extra: Shipped off to go rebuild her country in the Michel arc.
- Early-Bird Cameo: Her introduction in the anime, where she wins the beauty contest out of nowhere.
- Image Song: "Aurora no Kaze ni Notte" ("Riding on the Winds of the Aurora").
- Ineffectual Loner: She tries to save Noel by herself and fails miserably, only effective when she's around the others.
- I Was Just Passing Through: Caren pulls off a few rescues out of nowhere and just leaves.
- Knight Templar Twin Sister: You hurt Noel? Oh, and all the other princesses and all the civilians in their countries — no, who cares about that. Noel is enough motivation to run at you in a rage.
- Let's Get Dangerous!: End of the manga with Noel and Coco.
- Mysterious Watcher: She hangs around in the shadows watching the main trio for a while before meeting them.
- Nay-Theist: Early on, she refuses to acknowledge Aqua Regina despite knowing full well that she exists. She's not outright denying it, but she does say that Aqua Regina never did anything for her or Noel.
- Nice Job Breaking It, Hero!: By refusing the trio's help, she gets captured.
- Polar Opposite Twins: With Noel. Caren is sarcastic and jaded, Noel is gentle and soft-spoken. To emphasize this, they're actually from the North and South Poles.
- Purple Eyes: In her mermaid form.
- Rapunzel Hair: At one point, Tarou mistakes her for Sara because of it from a distance.
- Red Oni, Blue Oni: With Noel. Caren's the red, being angry and loud in comparison.
- Regal Ringlets: Huge curls in her long hair.
- Significant Birthdate: Caren is a Defrosting Ice Queen who says there's not much point to love if duty will always come first but becomes a Shipper on Deck when she gets closer to the younger girls and starts to care about their love lives instead of try to ruin them. Her birthday is Valentine's Day.
- West Coast Team: In the second arc, she, Noel, and Coco act as one.
- You Gotta Have Blue Hair: She has purple hair.
- You Shall Not Pass!: She, Noel, and Coco stall the Winged Beings in the second arc's finale with this.
Princess of the Arctic Ocean who was imprisoned by Gackt before the start of the series. Also the twin sister of Caren.
Tropes associated with Noel:
- Beauty Mark: Under her right eye.
- Blue Oni: To Caren.
- Bookworm: Noted in episode 71.
- Gender-Blender Name: Many translators thought her name was "Noelle" because they'd only seen men called "Noel."
- Meaningful Name: Because she's from the North Pole.
- Meganekko: Noel owns a pair of reading glasses she wears specifically to try and look smart.
- Nice Girl: Noel is kind and gentle to everyone she meets.
- Out of Focus: Unlike Caren and Coco, she never gets her own episode in Pure.
- Polar Opposite Twins: With Caren. Caren is sarcastic and jaded, Noel is gentle and soft-spoken. To emphasize this, they're actually from the North and South Poles.
- Raven Hair, Ivory Skin: She's the palest mermaid and has the darkest hair.
- Yamato Nadeshiko: She's the quietest, most mature mermaid. Anime filler kind of ruins this characterization by making her go along with Caren's and Coco's zany schemes, though.
- You Gotta Have Blue Hair: Has dark blue hair.
Princess of the South Pacific Ocean who suffered the same fate as Noel, but unlike Noel, the audience doesn't get a good look at her until the end of the first season.
Tropes associated with Coco:
- A Day in the Limelight: Episode 12 of Pure features her as a main character and her search for Sara's spiral shell kicks off the plot.
- Cloudcuckoolander: She's out there in the anime. Sometimes to the annoyance of the others.
- Genki Girl: Her personality in the anime. She's more mature in the manga.
- Hair of Gold, Heart of Gold: While she surrendered, it was out of a desire to help.
- Hime Cut: Has this hairstyle. It's especially fitting considering that she is a princess.
- It's All My Fault: Feels guilty for not being able to appease Sara.
- Meaningful Name: Considering how she is associated with tropical islands...
- The Tease: Noted in episode 71.
- Undying Loyalty: To her childhood friend Sara, especially in the manga. Coco never gave up on Sara and even allowed herself to be kidnapped so she could have a chance to try and help Sara.
Sara first appears as a mysterious figure in Gackto's castle, stealing all his attention from the Dark Lovers and making them jealous. The truth is, Sara has been there all along, directing Gackto from behind the scenes. She does what she wants, when she wants, whether it helps or hinders Gackto's plans, and strings him along to agree with it by flirting and pulling rank, the exact same way he treats his Dark Lovers. Sara has had her heart broken in the past, and no longer believes in love, hope and freedom. Her objective now is to take revenge on all the world, but at times, what remains of her heart can get in the way - which Lucia and company will need to exploit if they want to summon Aqua Regina.
Tropes associated with Sara:
- Broken Bird: She's the way she is because she believed her lover abandoned her.
- But Not Too Evil: The lyrics of the Italian version of her song say the exact opposite of what the original said, making her sound like a good guy. But also partially justified by the fact that either due to either laziness or genuine budget issues the Italian dub decided to recycle "Assoluto Amore" for Sara's successor Seira, your mileage may vary on how successful the execution is though... especially considering Seira's singing voice is the SAME as Sara's!
- Dark Magical Girl: She's twenty-three, but it fits.
- Dark Reprise: "Return to the Sea" reverses this.
- Disproportionate Retribution: She wants to destroy the world simply because she believes that a human she fell in love with abandoned her.
- Evil Costume Switch: Sara was originally an orange Mermaid Princess with more frills and less black.
- FaceHeel Turn: Before the beginning of the anime/manga.
- Fan Nickname: Black Sara.
- HeelFace Turn: In the end of the Gackt arc, spoiled by merchandise.
- Image Song: "Return to the Sea."
- In the Hood: Wears a veil to hide her face.
- I Was Just Passing Through: She foils the Black Beauty Sisters' attack once, despite still being on the same side, and disappears soon after that.
- Last Chorus Slow-Down: The second half of "Return to the Sea" is slow-paced and nostalgic compared to the fast, almost angry tone of the first half.
- Love Makes You Evil and Love Redeems. Sara was driven to desperation and wanted to take her pain out on the world for being betrayed, but in the end, she realizes that it might have been for the greater good — though she still doesn't learn that Tarou was set up — and her acknowledgement that Gackt was always there for her leads her to confront him and bring him over to the good side too.
- Man Behind the Man: To Gackto.
- No-Sell: She's immune to the other princesses' Magic Music. While the anime presents it as it being hard-wired into their powers that mermaid songs can't harm other mermaids (without explaining why Sara is able to hurt them with her music), the manga goes with the idea that Lucia and co. can't hurt Sara with their songs is because she's just that strong.
- Paint It Black: Her transformation from good (in orange) to evil (with black hair and, in the manga, a black dress) is the page image.
- Pinocchio Syndrome: If Sara had only been human, we could have avoided all of this.
- Rapunzel Hair: Tarou considered it her Distinguishing Mark.
- Rebellious Princess: Sara was a selfish version of this, who wanted to abandon her country for love.
- Redemption Equals Death: Her end in the anime.
- Redemption Earns Life: She is revived in the last episode. In the manga, she's still dead.
- Schrödinger's Cast: She stays dead in the manga but revives in the nonsensical last episode of the anime.
- Sealed Good in a Can: Her end in the manga.
- Spirit Advisor: Takes this role in the beginning of the Michel arc.
- Starcrossed Lovers: The series is full of this, manga especially, but her particular situation caused the entire story.
- Villain Song: "Return to the Sea" is hers.
- Where I Was Born and Razed: Invaded her own country and was the mastermind behind the rest.
Major first arc spoilers here. Lucia, following Sara's last instructions, took the orange pearl to the Indian Ocean to create a new Orange Pearl Voice. The little girl, Seira, didn't fully emerge before Michel ambushed them and absorbed most of her life force. Now Seira is trapped as a spirit, much like Aqua Regina had been, inside the pearl, and much of the quest of the second arc focuses on getting back the pieces of her heart.
Tropes associated with Seira:
- Become a Real Boy: Her arc is about regaining all her emotions and being born for real.
- Big Damn Heroes: Near the end of Pure, she rescues Lucia, Hanon, Rina, and Kaito from Michel. Unfortunately, she's taken hostage as a result.
- Bratty Half-Pint: Though she gets a lot better when she learns more emotions.
- Character Development: As she regains her lost emotions, she becomes kinder and more empathetic. In fact, she actually tries to reach out to Michel (the being who stole her emotions in the first place) because she can sense he's lonely and in pain.
- Damsel in Distress: One of the main plotlines of the second season is about rescuing her from Michel. They even make it a point to remind us at the beginning of every other episode.
- Heroic Sacrifice: But doesn't die.
- Image Song: "Beautiful Wish" and "Birth of Love."
- It's All My Fault: Ends up blaming herself in part for all the pain Lucia went through to try and save her.
- Kid-Appeal Character: She would logically be a baby, but she looks and acts like an elementary school-aged child. Definite kid appeal here.
- Lack of Empathy: Through most of the Pure/Michel arc, Seira's heart is fragmented, and she only gains emotions after Lucia and company win them back. Until then, she's selfish and doesn't understand why Lucia is so sad about her failures and her amnesiac boyfriend.
- Rapunzel Hair: Like every mermaid.
- Someone Has to Do It: Seira was born specifically to fill the void Sara left.
- Sympathy for the Devil: In relation to Michel.
- What Is This Feeling?: Throughout the season she learns what love, friendship, heartbreak, etc. feel like.
- Younger Than They Look: She's only been born, but looks and acts in the 6-10 year old range.