The main protagonist of the series. Sora has dreamt of becoming part of the Kaleido Stage ever since her deceased parents took her to see a performance as a child. With her adoptive parents' hesitant approval she travels to the United States to audition. Although she can't make it to the audition, the owner Kalos becomes interested in her skills and lets her join the Stage after he has her perform in an actual show. Most of the cast are dissatisfied with Sora due to the special circumstances through which she joins, but they accept Sora due to her persistence and hard work along with her magnetic personality.
- All-Loving Heroine: This girl has almost unlimited love and kindness towards everyone, no matter what happens.
- Break the Cutie: Has to go through LOTS of hardship as the performing world isn't half as pretty and rose-tinted as she thought it was.
- Broken Messiah: When at her lowest points.
- Butt-Monkey: She is never safe from the world's abuse, whether it's being ridiculed by her fellow performers in Kaleido Stage.
- Desperately Looking for a Purpose in Life: In the second season, where she begins to have actual doubts about her talent.
- The Ditherer: In the second season, she decides to create a "conflict-free stage" and goes as far as to decline Cathy's offer to app for the role of Juliet to "avoid" another conflict with May. May even calls her out on it, telling her she's running away from her troubles.
- The Friend Nobody Likes: Almost everyone at Kaleido Stage has expressed dismay about her quirks.
- Genki Girl: When not in self-deprecating moods, she's energetic and spirited.
- Happily Adopted: After her biological parents died, she was taken in by her dad's cousin and his wife, who loved her as much as if she was their real child.
- Heroic Self-Deprecation: The girl tends to have a pretty low self-esteem and at times can fall in crippling depression.
- Innocently Insensitive: She's so oblivious to Ken's feelings for her that keeps treating him as just a friend and missing the obvious signs that he loves her.
- Oblivious to Love: She has no idea of Ken's crush on her.
- Parental Abandonment: Her biological parents died before the start of the series.
- Plucky Girl: Big time.
- Romantic Two-Girl Friendship: With Rosetta.
- Rose-Haired Sweetie: She's got dark pink hair and a cheerful and optimistic personality.
- She's Got Legs: The camera tends to focus a lot on her long, shapely, lovely legs.
- Ship Tease: Mostly with Ken, Layla and Rosetta.
- Town Girls: The Neither to Mia's Femme and Anna's Butch.
- Wide-Eyed Idealist: And one who manages to not become a Knight In Sour Armor!
- Woman in White: Sorta, her leotard is white.
- Unskilled, but Strong: Sora has lots of stamina and strength, but next to no skills since despite having been a Passionate Sportsgirl, she hadn't specifically trained in acting and gymnastics. Hence why she has to go through Training from Hell.
- You Gotta Have Blue Hair: Her hair is raspberry-hued, which stands out because even the other native Japanese who visit her have realistic hair colors.
The daughter of Laura and Kevin Hamilton, Layla is accomplished and seasoned, but arrogant and perfectionist performer of Kaleido Stage. At first rivals with Sora, Layla becomes friends with her. Layla has a strained relationship with Kevin, who attempts to force her to become an actress and is frequently trying to push her into doing so. However, Layla joined the Kaleido Stage due to her fondness for the Stage, as Laura has gone there during her youth.
- The Ace: The prima donna of the Stage in every sense of the phrase.
- Broken Bird: The death of Laura and her emotional distance from Kevin, her good-hearted yet workaholic father have left deep scars in her heart.
- Brutal Honesty: She is always blunt with her words and actions.
- Calling the Old Man Out: She calls out Kevin after returning from London to participate with Sora and her allies in Vancouver.
- Career-Ending Injury: Performing the "Great Legendary Maneuver" with an almost broken shoulder injured Layla so badly that she won't be able to perform again in the Stage. She's next seen in Broadway.
- Dislikes the New Guy: She has no trouble expressing how low her opinion is about Sora when they first meet.
- Icy Blue Eyes: Matching her aloof demeanor.
- Jerk with a Heart of Gold: She seems at first to be an arrogant, ultra-perfectionist who won't let newbies catch a break, but soon we see that she's as hard (if not more) on herself as she is with others and that she loves the Kaleido Stage as much as Sora does.
- Knight In Sour Armor: As seen above, Layla is a sad and almost embittered young woman who loves the Stage with all her heart but has lost her initial joy. Sora helps her regain her more idealistic side.
- The Lancer: She becomes Sora's best ally during the first season.
- Lethal Chef: Can't even handle a coffee machine.
- Mentor Archetype: She becomes Sora's mentor by the time the second season rolls around.
- Ojou: Of the Ice Queen type.
- The Perfectionist: She demands nothing but perfection from others and especially from Sora and herself.
- Plucky Girl: As stubborn as she's skilled.
- Rapunzel Hair: Her long and flowing hair reaches down to her waist.
- Took a Level in Kindness: As Sora reaches for her, she begins to slowly defrost and show her gentler sides to the point that she reconciles with Kevin.
- "Well Done, Daughter!" Girl: Laura is dead, and Kevin is kind but always at work. Young Layla swore to make her dad proud.
The mysterious spirit of the Kaleido Stage. He appears to Sora shortly before she appears on the Kaleido Stage for the first time.
- Butt-Monkey: He tends to be ignored, punched, yelled at by Sora.
- Cool Mask: A really cool-looking half-mask.
- Fairy Companion: A Deconstructed Trope. Sora thinks she has lost her mind when she starts seeing him, his advice isn't exactly flawless, and when Sora goes into borderline Wangst status she actually stops seeing him for a while.
- Fortune Teller: In the first season, he reads the future by drawing a single tarot card. In the second season, he reveals the hidden workings of inter-character relationships, associating each character with a sign of the zodiac and stating how some signs are dimmer or brighter.
- Lovable Sex Maniac: A pervert who tries many times to see Sora, and sometimes her friends, naked (usually by suggesting that they should take a shower). Sora is quick to prevent Fool from peeking in any given situation by trapping him somewhere or rebuking him forcefully.
- Invisible to Normals: He's invisible to everyone but those who are destined to do great things on the stage and/or whose heart is completely dedicated to the stage.
A close friend of Sora's. Mia is passionate about writing the scripts for Kaleido Star's performances and she has a keen interest in introducing literature into Kaleido Star's acts.
- Badass Bookworm: She's a really Cute Bookworm, yes, but has also lots of genuine atheltic skills
- Fiery Redhead: Mostly averted, though she has her moments as well.
- Girlish Pigtails: She arranges her hair like this
- Town Girls: The Femme to Sora's Neither and Anna's Butch.
Another good friend of Sora's. Anna is talented in many areas and frequently plays more serious parts. Anna truly wishes to perform comedy and usually tries to get Mia to write comedy into her parts.
- Bifauxnen: She's tall and pretty, but in a boyish way. She often takes up boyish rolesd as a result, and has MANY female fans specifically for this
- Boyish Short Hair: Sora and Mia are girlier than she is, and unlike them she keeps her Messy Hair short.
- Calling the Old Man Out: Anna expresses her disappointment in Jack when she finally confronts him, but they quickly reconcile shortly afterward.
- Cross-Cast Role: She plays male roles sometimes.
- Disappeared Dad: Jack "Baron Jack" Heart.
- Even the Girls Want Her: Has BUTTLOADS of female fans in-story, specifically due to her Bifauxnen-ness.
- Like Parent, Like Child: She and Jack are very similar.
- Sad Clown: She cracks (bad) jokes and seems to have a talent for comedy, but Jack's disappearance has left her really sad.
- Town Girls: The Butch to Sora's Neither and Mia's Femme.
- You Gotta Have Blue Hair: Has light purple hair.
A world champion diabolo performer. After her first performance at Kaleido Stage, Kalos kicks her off the stage because her act was unsatisfying: he explains that despite being perfect in the technical field, she lacked passion at what she was doing, so everyone was bored by her act. Feeling this wasn't fair, Sora takes the girl under her wing, teaching her how to put audience enjoyment before technical perfection. In return, Rosetta teaches Sora diabolo, which Sora returns to when she needs help learning new acts. Later in the series, Rosetta returns to join the Kaleido Stage in a permanent way.
- Defrosting Ice Queen: It took her only one episode to melt.
- Fiery Redhead: As soon as she befriends sora, she lets her more hotblooded side arise
- Lethal Chef: A Justified Trope: she's at much 14 years old and has never lived alone.
- Tomboy and Girly Girl: She's the Tomboy to Sora's Girly girl.
A young girl living near the Stage. Her father is a designer and engineer and works on the sets, but her mother Cynthia was a trampolinist who died due to an accident. In the second season Marion begins to perform with the group on the Children's Stage.
- Bratty Half-Pint: Also for one episode.
- Circus Brat: Her dad is the lead of the stagehands, her dead mom was a Kaleido artist. In the second season, she officially joins the Stage.
- Tagalong Kid: The youngest of Sora's friends, and she isn't an official part of the stage until later.
- "Well Done, Daughter!" Girl: To her Missing Mom.
A baby seal that Sora picked up one day. Unable to keep pets, Sora tries to hide him. However, the secret is revealed and instead of kicking him out, Marion's father builds a tank for him. He is capable of doing many tricks and sometimes seems more coordinated than Sora, creating comical performances that the attending children love.
- Empathy Pet: To Marion.
- Sweet Seal: A cute little baby seal that Sora adopts.
An experienced performer who usually performs with Layla.
- Reformed, but Rejected: Considering that he did pull lots of shit on the Stage, this is understandable. Thankfully this is later subverted.
- Sixth Ranger: Second season.
- Token Evil Teammate: First season.
- You Killed My Father: Believes Kalos to be responsible for his father's death.
A Chinese-American new recruit who challenges Sora's position. She became jealous of Sora because of the bond she formed with Layla.
- Armor-Piercing Slap: To Sora, when she declines Cathy's offer to app for the role of Juliet. May, already emotionally distraught for a short while, snapped so badly that she started screaming at Sora and then slapped her in ront of everyone.
- Break the Haughty: And holy shit HOW! Not only she falls victim to Leon's "curse" when he deliberately injures her to knock her off her pedestal, but later she gets called out more than once on her arrogance - especially by Layla, her own idol.
- Bare Your Midriff: She does that sometimes.
- Brutal Honesty: Has even less of a thoughts-to-words filter than Layla
- Child Prodigy: Subverted. May was an ice skating prodigy as a little girl, as revealed by her coach Meredith, but ultimately decided to ditch skating (thought she still skates once in a while) to focus solely on the Kaleido Stage.
- Cool Big Sis: She has multiple little brothers and sisters who see her this way. She would even teach her brothers wrestling moves.
- Don't You Dare Pity Me!: Her Berserk Button.
- Jerkass: At first.
- Jerk with a Heart of Gold: After her Break the Haughty induced Character Development.
- The Lancer: To Sora in the second season as it goes on.
- Large Ham: Thanks to loudly calling Her techniques.
- Plucky Girl: When she gets over herself.
- Small Name, Big Ego: When she first shows up at Kaleido Stage, she thinks that everyone will just hand her all of the starring roles and she'll become a big name without even trying. Needless to say, a brutal Break the Haughty puts a stop to that.
- Spoiled Brat: Until she gets better.
- Tsundere: Extremely Type A, switches to Type B as she develops.
A very famous trapeze performer who arrives in the second season. He comes off as arrogant, refusing to perform with Sora, because she is not skilled enough for him. He tries to terminate his own contract very early on, but after seeing Sora and May Wong fight on stage, he decides to remain in hopes that one of them can become his true partner.
- Broken Ace: On one hand, he's famous, skilled and handsome. On the other, he's an arrogant Jerkass who practically tortures his potential partners to see their worth and is still traumatized by his beloved sister's death.
- Cynicism Catalyst: Horribly losing his Morality Pet sister Sophie drove him over the edge and very close to the Despair Event Horizon.
- Freudian Excuse: He looks and acts like a perfectionist, cruel, ice-cold Jerkass who practically tortures his potential partners to see their worth, but is later revealed to be deeply traumatised by the tragic death of his sister and partner Sophie, who went through exactly the same Training from Hell he subjects his partners to - and actually was successful, therefore both May Wong and Sora Naegino have to struggle hard to get his trust.
- I Let Gwen Stacy Die: He still blames himself for his sister's death.
- Jerk with a Heart of Gold: He starts off as a jerk to Sora, but overtime he becomes true friends with her.
- Kick the Dog: No matter what you think of May, not even she deserves to have Leon deliberately dropping her on-stage and causing her to get seriously injured. It's also mentioned that May is not the first one he's done this to, and his actions have crippled one of his former partners and killed another.
- Took a Level in Kindness: Compare the jerkass Leon from the second season beginning to the much less constipated one from the last episodes.
Kenneth "Ken" Robbins
The stage manager for Kaleido. He used to want to perform onstage when he was young, but claims to have a weak heart and decided that it was best to be backstage. He has a huge crush on Sora, something she's completely unaware of.
- Cannot Spit It Out: Two where Anna and Mia spend an episode trying to get him to confess to Sora.
- Dogged Nice Guy: To Sora, though he's not as pushy as others.
- Everyone Can See It: That he has feelings for Sora.
- Hopeless Suitor: Sora is far too dense to think of him as anything more than a friend, and nothing hints that will ever change.
- Ill Boy: Has a weak heart.
- Love Hurts: His crush on Sora brings him more angst than anything, since she genuinely sees him as just a friend.
- Tragic Dream: He's the busboy because his heart illness doesn't let him train and become a performer.
The main singer of Kaleido Stage, as well as the building manager for the dorms where everyone lives. Many want Sarah to sign on a record label because she is so gifted in singing, but she stays true to Kaleido Stage. She is an avid fan of martial arts, and frequently proposes bizarre alternative methods to help Sora achieve her objectives.
- Career Versus Man: She dreamt of becoming a world-famous singer, but after Kalos' Career-Ending Injury, she decided to become Kaleido Stage's singer so she could stay near him despite Kalos' protests.
- Idol Singer: She sings on the KS stage, and it's mentioned she's been offered CD contracts many times but has refused all of them.
The head manager and boss of the entire Kaleido Stage. He gives Sora many helpful pieces of advice throughout the anime. He also maintains high expectations of everyone he encounters.
- The Atoner: For something he didn't do.
- Break Her Heart to Save Her: In one episode, when Kalos felt as if Sarah should pursue her own dream, he tells her to leave with their old friend Andy since she's "no longer needed", leaving her in tears. His plan is ruined when Sora intervenes and forces him to confess his true feelings.
- Career-Ending Injury: He used to be a Stage Magician, but he injured his fingers and now can't perform magic tricks.
- Characterization Marches On: When we're introduced to him, his actions give the impression that he has a genial, Cloudcuckoolander sort of personality, but that impression does a very quick 180, and his tough-as-nails, Ice King sort of demeanor is revealed. It's practically a subversion of Establishing Character Moment. Though interestingly, his initial reactions towards Sora are brought back up later on.
- Engineered Public Confession: In order to let Sarah know how he truly feels, Sora goes to Kalos' office and teases him to reveal his true feelings. In the meantime, the others bring Sarah to the stage, and she listens to Kalos's words via Sora's hidden microphone.
- Hidden Heart of Gold: He exhibits stone-cold authority towards his crew, but almost no one matches his passion for showmanship.
- I Was Quite a Looker: Invoked by Sora when she sees a photo of his younger self (alongside a teen!Sarah and their companion Andy) and can't believe the baby-faced youth in the picture is him.
- My Greatest Failure: Has blamed himself for more than 10 years for the death of Yuri's dad.
- Self-Made Man: He started as a self-taught Stage Magician who performed in the streets. 20 years later he's the owner of the world-famous Kaleido Stage.
- Sink-or-Swim Mentor: While he sees potential in Sora, he's pretty relentless in pushing her beyond the limits of her experience.
- Team Dad: A rather stern one at that.
- Unwitting Instigator of Doom: He believes himself to be such, since he asked Aaron if he truly was up to performing the very dangerous Fantastic Maneouver... a few hours before Aaron failed to do it and died, which is the reason why Yuri is pissed off at him enough to try buying out the Stage as revenge.
Jerry, aka Mr. Policeman
A tall, muscled African-American policeman and Sora's self-proclaimed "1# fan".
- Childhood Friend Romance: With Kate the doctor.
An elderly man and representative for the Stage's stockholders. He is often portrayed as a producer, seemingly giving him executive powers often rivaling or superseding that of Kalos. He has great experience in show business and often aids Sora.
Leon's deceased little sister.
- All-Loving Heroine: Very sweet and kind, could never ever say a bad word about anyone.
- Fangirl: Of Yuri.
- Look Both Ways: How she died. Yuri tricked Sophie into being late for her and Leon's audition for a very important contest, and when she was running towards the stage with less than five minutes to spare... she carelessly crossed the street without glancing around and got fatally hit by a truck.
- Morality Pet: To Leon.
- Plucky Girl: She was as strongwilled as she was gentle.
The writer and director of "Salome In Vegas", an off-Broadway stage-play.
- Cool Big Sis: To Sora and especially to Mia.