Akari Mizunashi

The main character. An immigrant from Japan, Manhome who comes to Aqua to become an undine. Normally shown as a very cheerful person. Has a strange tendency to draw supernatural phenomena to her.

• Catch Phrase: "Ah, suteki!" and "Ha-hi!"
• Cloudcuckoolander
• Friend to All Living Things: Not only does she befriend nearly every human she meets, but several animals and even a snow bug as well. She even feels sorry for some chocolate candies that won't get eaten because they got dropped onto the ground!
• Genki Girl
• Love Freak: Probably everyone's trait, but it's especially apparent with Akari.
• Rapunzel Hair: Her "sideburns" get so long by the epilogue that she's able to loop them back around into a ponytail! How she doesn't catch her oar in those loops is anyone's guess.
• Romantic Two-Girl Friendship: Her relationship with Alicia certainly has elements of this, which culminates in the Arietta OVA.
• Rose-Haired Girl
• She Is All Grown Up: In the anime she's the only one out of her and her two friends that's shown after reaching adulthood
• Ship Tease: With Akatsuki, but also with Alicia, so much that Alicia's unexpected marriage outraged quite a few yuri fans.
• Tearful Smile: When Alicia "disappeared" after she told Akari she planned to retire.
• Weirdness Magnet:
• Wide-Eyed Idealist: Yes, even by ARIA standards.
• Yamato Nadeshiko: She's on her way.

Alicia Florence

One of the three Water Fairies, Akari's tutor. Current manager of ARIA Company. She's known by the title "Snow White", and is currently the most popular undine in the city.

• Catch Phrase: "Ara ara" almost always followed by a giggle.
• Last Minute Hookup: Gets married in the last chapter/episode with little/no foreshadowing.
• Onee-sama: So very much.
• Romantic Two-Girl Friendship: With Akari
• Sayaka Ohara
• Ship Tease: With Akari, most prominently in the Arietta OVA.
• Stealth Hi/Bye: Does this a from time to time, though it usually happens in the later chapters rather than the earlier ones.
• Yamato Nadeshiko

Akino Ametsuchi

Better known as Grandma. Legendary Undine and the founder of ARIA Company. Originally she's from Himeya Company, but break off after meeting with President Aria. Currently lives in countryside.

• Alliterative Name
• I Was Quite a Looker: She aged very badly, to say the least.
• Miniature Senior Citizens: Shrunk considerably between her working as an undine and now.

Ai

Originally an anime-only character. Ai is Akari's customer in the first episode of the anime (in place of an old man in the equivalent manga story), and serves as the character that Akari corresponds with (in place of her unknown readers in the manga). In the last chapter of the manga, gets Canon Immigrant treatment.

• Canon Immigrant
• Cheerful Child
• Last Episode New Character: In the manga.
• She Is All Grown Up: While she doesn't appear to physically grow during the 6 earth years that the series covers, that changes in the epilogue.

Anna

Grandma's apprentice before Alicia. Left the company after Alicia became Prima. Currently has a family.

• Hot Mom

President Aria Pokoteng

ARIA Company's president. Can be considered as a B Side main character. A Martian cat that Akino met, and with whom she founded ARIA Company.

• Really 700 Years Old: Stays with the company for 20 years and he doesn't look any different at all.

Aika S. Granzchesta

Daughter of the owner of Himeya and its heir. Akari's first friend on Aqua. Has a crush on Alicia and later Al.

• Catch Phrase: "Hazukashii serifu kinshi!" translatable as "Embarrassing remarks are not allowed!"
• Chiwa Saitou
• Grumpy Bear
• Important Haircut
• Jerk with a Heart of Gold: Though a very light version.
• Stalker with a Crush: In the beginning of the series, she exhibits this toward Alicia.
• Zettai Ryouiki: Only once in the anime, which was enough to leave a huge impression.

Akira E. Ferrari

One of the three Water Fairies, Aika's tutor. She's known by the title of "Crimson Rose" for her conversation skill with customers. Tomboyish enough that she can be considered as The Lad-ette (especially with Akatsuki mistaking her as a boy when they're children).

• Adult Child: Her rivarly with Alicia can be very petty.
• Expy: Probably from Senkoh Katori from Amano's earlier work Roman Club, considering that Akira's look when she was a kid is exactly like Senkoh. She might be Senkoh's descendant. That, or she's expy of his sister, Matou, who also appears in Amanchu!.
• Hard Work Hardly Works: Averted hard. The only reason she's able to be one of the Water Fairies is because she works really hard. As she said, she has no notable talents like her friends Alicia or Athena have, so hard work is all she can do to make up for it.
• Junko Minagawa
• The Lad-ette: Except the drinking part — she can barely hold liquor, especially compared to Alicia, who can hold massive amounts.
• Tall, Dark and Bishoujo: The Poster Girl

Ayumi K. Jasmine

One of the trainees that Akari met when she works at Traghetto. Quite a cheerful person.

• I Just Want to Be Normal: Well, more normal. She doesn't even want to be a Prima at all.

President Hime M. Granzchesta

Himeya's president. A cat from Manhome. Quite aloof. President Aria has a crush on her.

• Tsundere

Alice Carroll

A trainee for Orange Planet. Is considered to be a prodigy because of her gondola skills despite the fact she is still in middle school when she is recruited. A real Deadpan Snarker.

• Alice Allusion
• Catch Phrase: Uses "dekkai" (huge) in every other sentence, if not more.
• Child Prodigy: Nearly flawless rowing skills even when still a pair. She also becomes an Undine before her seniors Akari and Aika.
• Defrosting Ice Queen: Starts out as this, mellow out very quickly.
• Innocent Prodigy: Although hidden under her antisocial personality and her status as a prodigy, she's still shown to have an adorably childlike naivety at times.
• Little Miss Snarker
• Ryo Hirohashi
• Self-Imposed Challenge: She likes to go home from school in various creative ways, such as kicking a rock along the path or only walking on shadows. These often cross into Just a Kid territory.
• Ship Tease: With Woody (only in the manga).
• Shout Out: Probably Is to Lewis Carroll and Alice in Wonderland
• Sugar and Ice Personality: Quite antisocial on the surface.
• Wise Beyond Their Years: Although even with that, she's still 14 and it shows.
• Zettai Ryouiki: In her school uniform.

Athena Glory

One of the three Water Fairies, Alice's tutor. She's known by the title of "Siren" for her beautiful singing voice. Very clumsy (but see below).

• Cloudcuckoolander: Even more so than Akari.
• Dark-Skinned Blond: Okay, actually Dark Skinned Purple, but still fits.
• Dojikko
• Easily Forgiven: She has the tendency to pull rather mean pranks (like faking amnesia), especially on poor Alice, but always manages to get away with it.
• Genius Ditz / Obfuscating Stupidity: Is actually capable of not making mistakes, but usually doesn't bother when she's not on the job because it's "too tiring".
• Meaningful Name
• Tomoko Kawakami

Atora Monteverdi

One of the trainees that Akari met when she works at Traghetto. A bit of Yamato Nadeshiko herself.

• Yamato Nadeshiko

Anzu Yumeno

One of the trainees that Akari met when she works at Traghetto. Very shy.

• Determinator: Has failed the Prima exam several times, but hasn't given up yet.

President Maa

Orange Planet's president. Originally found as a stray by Alice, who picks her up to take care of. Has a habit of biting President Aria's belly.

• Your Tomcat Is Pregnant: Was thought by Alice to be a male cat until the vet reveals this fact. Without the pregnancy, though.

Akatsuki Izumo

He works in one of the floating islands as a Salamander, controlling weather on the planet. Has a crush on Alicia (who claims to assume instead it's on Akari). Akari's first customer.

• Adult Child
• Bishounen
• Ship Tease: with Akari
• Stalker with a Crush: Mild version, mind you.

Ayanokohji Udo the 51st

Better known as Woody, he works as Sylph, an airbike courier delivering goods in a city without streets. Has quite a bad sense of direction.

• No Sense of Direction: His first appearence have him lost a map and need Akari's help to navigate the city.
• Transplant: It's either this or he's descendant from Ayanokohji Udo from Amano's earlier work Roman Club considering that they have same name, look, and even personality.

Albert Pitt

Working as a Gnome, people who works in gravity control system underground. Aika has a crush on him. Older than he looks.

• Don't Explain the Joke: He always does when he makes an-
• Incredibly Lame Pun: He often makes "old man" jokes with these. They're so old (and originally from Manhome) that he has to explain them every time.
• Soap Opera Rapid Aging Syndrome: The only logical explanation for him growing at least a foot taller at the end of the final episode but before the timeskip epilogue.
• Stealh Hi Bye: Happens every now and then.
• Older than They Look: Looks like a cute little boy, even though he's 18.

Anno Namihei

Better known as Mr. Postman, as Akari calls him. Works for the Neo-Venizia post office and gives Akari first trip in gondola. His name is not revealed until near the end of the series.

• Everyone Calls Him Barkeep: An Omake lampshades this, with everyone calling him not by his name, even though he has a nametag.
• Eyes Always Shut: The only time he opens them is when Akari narrowly avoids crashing, seen here.

Cait Sith

Mysterious Mega Neko that appears throughout the work, especially when the supernatural is involved, to Akari especially. Is the King of the Cats of Neo-Venezia, named after the king of the cats of Scottish folklore, and it is strongly suggested he is a guardian spirit of Aqua.

• Big Damn Heroes: Saves Akari from the ghost Woman in Black.
• Mega Neko