"I'd never lie to you, Vivian...I swear it..."One of the two protagonists of the series, Koops has changed quite a bit from his game self. He's still a bit of a coward, but he knows how to stand up for himself and others. He eventually develops feelings for Vivian. He is a descendent of the Stalwart Koopa of the Four Heroes. In the future, he becomes mayor of Petalburg and is married to Vivian, with two kids. He controls the Diamond Star.
- Adaptational Badass: As stated above, he's not quite as cowardly and timid as he was in the game.
- Ascended Extra: Not him, but his not really girlfriend Koopie Koo has a much larger role in the story.
- Berserk Button: Anything that can harm Vivian. In addition, he absolutely slaughters Beldam when he is forced to kill Vivian.
- Beware the Nice Ones
- Cowardly Lion
- Dark and Troubled Past: His mother was eaten by Hooktail. Right in front of him.
- Famous Ancestor: He is a descendent of the Stalwart Koopa.
- Let's Get Dangerous!: The final battle, big time.
- Opposites Attract: Him and Vivian.
- Switching P.O.V.: Between him and Vivian.
"I promise I'll come back one day...and I never break promises..."One of two protagonists in the series. Vivian is similar to her game counterpart, still timid and frequently apologising. After suffering Beldam's punishments for too long (being a lot more violent then they're hinted to be in-game), she joins Mario. However, it's actually a trick that Beldam forces her to do to get the Crystal Stars. After realizing she can't bring herself to steal them, Vivian joins Mario for real. She controls the Ruby Star, as well as the Amethyst Star.
- Apologises a Lot
- Beware the Nice Ones: Especially when the nice ones have control over the Amethyst Star.
- Break the Cutie: After defeating the Shadow Queen, she is deserted by her sisters, can't contact any of her friends, and eventually decides to just walk through the desert to Poshley Heights. Keep in mind the desert is so long it takes three days by train to cross...
- Dark and Troubled Past: Her sister, Lillian, who was always nice to her, was killed by Beldam while the latter was trying to kill Vivian as a baby. Doubles as a Tear Jerker.
- Dark is Not Evil
- Deliberately Cute Child: She is forced to use this method in an attempt to seize the Crystal Stars.
- The Exile: Beldam forces Vivian away from their house, leaving her to wander alone.
- Fiery Redhead
- Not a Morning Person: She has trouble waking up, and even then she's still groggy for a while.
- Older Than They Look
- Opposites Attract: Her and Koops.
- Shrinking Violet: At first. Though this never really disappears completely.
"Did this talk include holding hands?"A Goomba girl and, apparently, Koops' only real friend before Vivian showed up. She helps Koops out with Vivian when he feels stuck. It is eventually revealed that she is a descendent of the Wise Goomba, Goombertha, of the Four Heroes. She controls the Crystal Star.
- Headbutting Heroes: With Waffles and Ms. Mowz.
- The Lancer: To the entire group, while Mario's around.
"I thought this was supposed to be a relaxing trip...we haven't been here for five minutes and already someone's threatening us."A cloud spirit and one of Vivian's closer friends. She gives Vivian her necklace after the Shadow Queen is defeated, since she was the one who found it back in Boggly Woods. She controls the Emerald Star.
"Ooh, I want 10 Shroom Roasts!"The light blue Yoshi baby from Glitzville. He treats a lot of people pretty horribly, Vivian especially, but he actually cares a lot about his teammates. He is a descendent of Nero of the Four Heroes. He controls the Gold Star.
"What he's doing for Vivian...I find it heartwarming and honorable. Why, I would do the same thing for my darling Scarlette..."Admiral Bobbery, a sailor Bob-Omb from their trip to Keelhaul Key. He joins the team when Vivian is poisoned and Koops stays at camp to watch over her. He controls the Sapphire Star.
"You belong with Mario...he'll never betray you and we'll all stand by your side until the very end. Like true friends should."A white mouse with a heart-shaped tail with excellent thieving skills. She seems to know a lot about Shadow Sirens, the Four Heroes, and a lot more, as well as being able to find information on them all. She reveals herself to actually be Teresa, a.k.a. the Boo Heroine of the Four Heroes. She was pardoned of her death to prevent horrible things from happening, but dies at the end with her mission complete. She controls the Garnet Star.
- Miss Exposition
- Older Than They Look
- Pet the Dog: After Koops is forced to kill Vivian, Ms. Mowz reveals her true self and revives Vivian.
- The Reveal: She is the Boo Heroine.
MarioMario is, for the first portion of the story, a major character. He leads the group around, just like in the game. However, after the Shadow Queen is defeated, he leaves the story completely, as it revolves around the partners rather than him.
- Heroic Mime: Though Goombella can apparently understand him.
- The Hero: Well, technically yes, but the story doesn't actually revolve around him. He is still the leader until partway through.
- Only Sane Man: While he's still in the story.
- Put on a Bus: After the Shadow Queen is beaten, he leaves, just like in the game. He does not return, though he is mentioned occasionally.
- Screw This, I'm Outta Here!: Downplayed and Played for Laughs; at one point, when the partners get into a huge argument, he just walks away towards their destination, knowing they'll follow him once they realize he's gone.
"I see you're taken with Vivian..."Vivian's older sister and Beldam's younger sister. She loves Vivian but is sometimes forced to attack her. She sometimes takes care of her whenever she's hurt or hungry. It's implied that Beldam forbid her from talking at the end when she suddenly begins talking. She then goes to live in Shwonk Fortress.
"You will address me by my name, not relations!"The oldest sister of Vivan and Marilyn, Beldam is even worse than in the games. She constantly beats Vivian for failing and blames all problems on her.
The Four Heroes
The Stalwart Koopa
"Alright. I guess you guys win. No point in being a leader when everyone overrules you, anyway..."The leader of the Four Heroes. His real name is Kevin, though his title is the Stalwart Koopa. Despite his rivalry with the Shadow Sirens, he ends up falling in love with Lillian.
- Ascended Extra: In the original game, the Stalwart Koopa was only mentioned in an optional story that players could easily go the entire game without reading. This applies to all of the heroes, actually, with the exception of original characters Nero and Lillian.
- Attention Deficit... Ooh, Shiny!: Hinted at; he says he has a tendency to walk away when people tell him to stay still. Never actually happens though.
- Character Alignment: YMMV, but he's most like Chaotic Good, or even Chaotic Neutral.
- Jerkass: Acts like this just about all the time.
- Noodle Incident: Whatever happened between him and Lillian at Creepy Steeple, but it's not too hard for the readers to guess.
- Red Oni, Blue Oni: The reddest.
- The Hero
The Boo Heroine
"I mean, what would the Four Heroes be without a leader?"One of the members of the Four Heroes. Her real name is Teresa, and she supposedly used to be in a relationship with Kevin. She later becomes Ms. Mowz to prevent Beldam from taking over the world.
The Wise Goomba
"I'd like to get some reading in on our down time, and you're making it really hard to concentrate."Also known as Goombertha, she is another member of the Four Heroes. She spends most of her time reading to gather information about the Crystal Stars.
- Ascended Extra
- Deadpan Snarker
- Headbutting Heroes: With Kevin.
- Only Sane Woman: Lampshaded.
- Red Oni, Blue Oni: Again, blue.
- The Smart Girl
The Toad Hero
"Just so you know...I used to live in this town..."The Toad Hero, A.K.A. Aaron, is the fourth member of the Four Heroes. He often uses a bow and arrow to fight with, and is usually quiet.
- Ascended Extra
- Flanderization: In the game, the Toad Hero was said to be "strong of arm, but shy of voice" only once. In this story, being shy and quiet is practically Aaron's defining characteristic.
- Nice Job Breaking It, Hero!: He shoots Lillian with an arrow, injuring her and causing Kevin and Nero to be caught by guards.
- Red Oni, Blue Oni: Once again, blue.
- Shrinking Violet
- The Big Guy
- The Quiet One: Doesn't speak much.
NeroAn original character who is technically not one of the Four Heroes. He is Kevin's friend and steed, being a Yoshi with wings.
- Big Eater: He's a Yoshi, after all.
- Red Oni, Blue Oni: Red, just like Kevin.
- Team Pet: To the whole group, but to Kevin he's...
- The Lancer
- Vitriolic Best Buds: Him and Kevin.
"So, what're you gonna do? Kill me in broad daylight? Do you even have the guts?"Another original character and Vivian's sister. She is also known as Princess Flora and watches over Vivian as a baby. Beldam murders her while attempting to murder Vivian.
- Berserk Button: Do anything to hurt or upset Vivian and you will regret it!!!
- Heel–Face Turn: Never was evil, per se, but she joins the Four Heroes at the end of their arc.
- Mama Bear: Not a mother, but she's very protective of Vivian.
- Red Oni, Blue Oni: Believe it or not, red. She's always sneaking out of the palace and doing dangerous things, as well as trying to free Kevin when he gets captured.