The Galilei Sisters
- Affectionate Nickname: They refer each other with nicknames.
- Blonde, Brunette, Redhead: Hazuki, Kazuki and Hozuki, respectively.
- But Not Too Foreign: Half-Japanese on their father's side.
- Color-Coded Characters: Hozuki is red, Kazuki is blue, and Hazuki is yellow
- Freudian Trio: Hazuki is The Mccoy, Hozuki is The Kirk and Kazuki is The Spock.
- Heroic Lineage: Direct descendents of Galileo Galilei.
- Multi-Ethnic Name: Japanese given names, Italian surnames.
- Red Eyes, Take Warning: The three of them have reddish-purple/magenta eyes.
Voiced by: Rina HidakaThe youngest sister at age thirteen, as well as the most brilliant. Shy and apologetic, but also extremely dangerous thanks her versatile arsenal of inventions.
- Affectionate Nickname: She is called Hocchii or Hocchibi by her sisters.
- Animal Motif: Goldfish.
- Apologetic Attacker: She's really sorry she destroyed your Humongous Mecha, Mr. Bad Guy.
- Badass Adorable: Cute, tiny, awkward... has a self-built arsenal of high-tech weapons, including a flying mecha-goldfish with homing missile launchers and a machine gun. She is afraid to use them, but that won't stop her.
- Beauty Is Never Tarnished: Falls from several stories high onto a pile of cars in episode four, and doesn't have so much as a scratch or bruise.
- Beware the Nice Ones: They may employ heavy artillery.
- Child Prodigy
- Daddy's Girl: And is not happy that the new security arrangement means she'll have to live with mom instead.
- Gadgeteer Genius: builder of a transforming rocket-scooter-gun and a flying mecha-goldfish, among other things.
- Girlish Pigtails
- I Let Gwen Stacy Die: She still feels rather unnerved by Leo's death and her inability to stop it; when Roberto starts a killing spree at the hospital, she's the one to stop him, remembering her lost friend.
- Kid from the Future: When she ends up in Galileo's time.
- Kid Hero: Well, she's 13. But her childish personality certainly counts.
- Potty Emergency: Has a brief case of this in Episode 5.
- Science Hero
- Teen Genius: Only thirteen years old and she's already creating impossibly high-tech gadgets.
- Token Mini-Moe: The youngest character of the series.
- Wrench Wench
Voiced by: Rumi OokuboThe middle sister, a seventeen-year-old high-schooler. Moody and lovelorn, but also a capable blackbelt.
- Action Girl: Black-suited man on top of you with a knife to your throat? Just crush his throat in first.
- Affectionate Nickname: She is called Kakki by Hazuki.
- All Love Is Unrequited: She has a crush on an as-of-yet unnamed boy at her school, but her fugitive status will likely keep her from getting the chance to confess.
- Aloof Dark-Haired Girl: Most of the time.
- Home Sweet Home: Kazuki really wishes her sisters would drop her off at home and leave her out of the whole "globetrotting fugitives" thing.
- I Just Want to Be Special: She's very jealous of Hozuki for her technical skills, and wishes that she could also live up to her lineage in terms of sheer talent.
- Ineffectual Loner: Known for skipping classes to escape group activities.
- Middle Child Syndrome: Good God, yes.
- Ms. Fanservice
- Proper Tights with a Skirt
- Refusal of the Call: She's very eager to give the Adni Moon company what they want, thinking that they'd let them go and leave them alone, allowing them to return to their normal lives.
- Second Year Protagonist
- Smitten Teenage Girl: Introduced skipping class and mooning over an unrequited crush.
- Third-Person Person
Voiced by: Kei ShindouThe oldest of the three sisters, twenty years old and studying law. Unfortunately for her, her late-night partying is threatening to get her flunked out of school.
- The Alcoholic: Sometimes doesn't even wait for the sun to go down before getting smashed.
- Big Sister Instinct
- Braids of Action
- Cloudcuckoolander: Her reaction to being slammed against the wall by a kidnapper? Attempt to negotiate an out-of-court settlement.Hazuki: Sexual assault is a felony! You'll get ten years for rape! Add assault to that and you can get a death sentence! We can settle out of court, but if you don't let me go right now, I'll press charges!
- Cool Big Sis
- Crusading Lawyer: Well, at least she wants to be.
- For Great Justice!
- Giving Someone the Pointer Finger: When listing off a criminal's transgressions.
- Hard-Drinking Party Girl
- Hot-Blooded: Gets really fired up about law, even if she's not terribly good at it.
- Lethal Chef: According to Kazuki.
- Nice Girl: She insists on giving some of their scarce food supplies to a homeless man they meet, she says that that's the right thing to do and people should help each other out.
Voiced by: Hiroshi KamiyaAn Italian Sky Pirate chasing after something referred to as "Galileo's Inheritence" who's oddly affable even when he's threatening to blow someone's head off. Enjoys flirting with the enemy, if only to annoy them. It turns out that most members of his band of Sky Pirates are people who were running away from abusive households and bad circumstances. He wants Galileo's Inheritance so that he can ensure they life comfortably and freely.
- A Father to His Men
- Affably Evil: He'll even invite his hostages to watch the World Cup prelims with him.
- Badass Bandolier
- Badass Longcoat
- Big Damn Heroes: He pretty much saves the girls in episode 3.
- Braids, Beads and Buckskins: Despite not being remotely Native American.
- Card-Carrying Villain: Regardless of whether or not he's actually evil, he certainly loves playing the part - just look at the grin on his face when he declares "We Will Meet Again!"
- Evil Redhead
- Foe Romantic Subtext: From his interactions with the Galilei Sisters, it's hard to tell if he sees them as Worthy Opponents or just has a giant Villainous Crush on Hazuki.
- The Gadfly: Especially when it comes to Hazuki.Cicinho: Girlie, what's your name?Hazuki: Hazuki Ferrari. Got a problem with it?Cicinho: Love it! Let me call you Bambina.
- Goggles Do Nothing: Except inform you that he's a Sky Pirate
- Gratuitous Italian: How else would you know he was from there?
- Honor Before Reason: Calls off his own attack on "Bambina" and her cohorts because they were distracted by Hozuki's almost-mortal injury, so he felt it wasn't a fair fight.
- Jerk with a Heart of Gold
- Laughably Evil: Cicinho appears to have gone into piracy not for the treasure but for teh lulz.
- Love at First Punch: While Hazuki didn't exactly punch him, when she stood up and verbally punched him it made him get interested in her.
- Lovable Rogue
- The Only One Allowed to Defeat You: Sorry, Roberto, but the privilege of screwing with Bambina (and thus Hozuki and Kazuki by proxy) is Cicinho's alone.
- Sailor Ponytail
- Sky Pirate
- Terms of Endangerment: Dubs Hazuki "Bambina" and flirts with her just to annoy her.
- Affectionate Nickname: Doesn't take long for "Bambina" to turn into this.
Voiced by: Marina InoueA self-admitted Galileo afficianado who wishes to track down or puzzle out anything he's ever left behind. She originally found herself in a situation not too different from the girls' upon learning of the Galileo Tesoro while researching her idol. She resolves to help the girls find Galileo's Inheritance and save their parents.
- All Love Is Unrequited: With Roberto.
- Anime Hair: Capable of hiding a cell phone.
- Ascended Fangirl: Very happy to go on a globetrotting adventure with the descendants of Galileo.
- Big Damn Heroes: She's the one to save Hazuki at the start of the series, and is in no small part responsible for the girls' escape.
- Double Agent: Is apparently working for Roberto.
- Green Eyes
- Love Martyr: She is willing to die for Roberto if necessary, but according to her, he couldn't care less.
- Oblivious Guilt Slinging
- Otaku: She's a Galileo otaku
Voiced by: Taiten Kusunoki
- "Death knows neither time nor place. It is fair and merciless to all, Cassini."
- An Arm and a Leg: His left arm and right leg are prosthetic. He lost them in the disaster that killed his parents, but got new limbs after the president of Adni Moon adopted him.
- Character Tic: Making origami.
- Corrupt Corporate Executive
- Dark and Troubled Past: Originally, he came from a wealthy family who taught him the importance of selflessness. Then a disaster that he barely survived killed his parents.
- Expy: Of Phoenix Wright.
- Freudian Excuse: His hatred of those he feels are drains upon society (read: pretty much anyone who isn't prim and exceptional) comes from how the homeless people his family fed chose not to help him when his parents were killed in a disaster, and instead chose to steal from his mother's corpse and ignore him when he was nearly crushed by debris.
- Happily Adopted: Sort of.
- A Man Of Wealth And Taste
- Red and Black and Evil All Over
- Start of Darkness: The deaths of his parents, along with the callous disregard the homeless people they had previously feed gave to the situation.
- Social Darwinist
- The Stoic: Calm, collected, and almost unflappable.
- Tall, Dark, and Handsome
- Used to Be a Sweet Kid
- The Unfettered
- Would Hurt a Child: Sometimes, the situation calls for the murder of a child or two.
- Wicked Cultured
Voiced by: Yuuki KajiYes, the real one. Hozuki travels to the past, falling on his aircraft. He's currently studying a strange phenomena on the sky. He has no idea Hozuki's his descendant.
- Beethoven Was an Alien Spy
- Birds of a Feather: With Hozuki, of course.
- Camp Straight
- Hair of Gold
- Intelligence Equals Isolation: Truth in Television. The real Galileo Galilei was tried and put into house arrest for his groundbreaking theories. He tells Hozuki about how alienated he got by everyone, to the point he didn't even want to discuss his dreams with anyone until she arrived.
- Long-Haired Pretty Boy
- Teen Genius: Well, duh.
- Time Travel Romance: He falls in love with Hozuki. He's blissfully unaware that she's actually his descendant, mind you.
- Walking Spoiler