The heroine of the game. She has lived all her life trapped in the village of Ertona, where nobody may enter or leave without the express permission of the Elder. As Firis has overly protective parents and no skills that would enable her to make a life for herself outside, she spends her days staring longingly at the one patch of sky visible from Ertona or at the huge door that leads outside...until Sophie and Plachta blast said door open, and introduce Firis to alchemy. Upon learning that the only way to become a licensed alchemist is to travel the world to seek out the letters of recommendation that would allow her to sit the exam in Reisenberg, Firis seizes her chance to escape Ertona. Armed with her new talent and accompanied by her older sister, she sets off to see the world and pursue a career as an alchemist.
- Big Eater: Constantly thinking about eating.
- Cloudcuckoolander: Due to her social isolation, she gets fascinated in very mundane things. For example, barrels.
- Gemstone Assault: Her unique attacks involve crystals. She throws them at an enemy with Stone Shot, makes them rain over a large area with Rock Call, and summons a large field of crystal with her Limit Breaks Corundum Heat and Corundum End.
- The Gift: Has a "talent" for seeing ores.
- Happy Rain: She likes the rain falling on her since she had never been exposed to it prior.
- Magic Staff: Like most Atelier protagonists, she wields a staff, but prefers to shoot magic bolts rather than use it as a melee weapon.
- Squishy Wizard: Even more than most Atelier protagonists. Firis has no physical attack, relying on her staff, her items, and her natural gift for communing (and attacking) with the earth. This is a Discussed Trope if you take Ren's test and choose "destruction" as your motivation, as Firis explains that she's powerless without the ability to use alchemy.
- Walking the Earth: Firis' motivation for learning alchemy is so she can get out of her confining hometown and travel the world. Of course, as an alchemist, she's always going to have a marketable job.
Firis' older sister. A hunter for the town who is trusted to leave Ertona relatively freely, she feels guilty that her younger sister remains trapped. She dotes on Firis, spoiling her with treats and gushing over her sibling's cuteness. However, she is experienced and capable in battle, wielding a bow and arrow. She becomes Firis' bodyguard and accompanies her little sister on her journey towards Reisenberg.
- Cool Big Sis: Cares a lot about her little sister Firis.
- Crutch Character: Early in the game, before you find more party members, Liane will be your only way to reliably deal damage without using up items.
- The Reliable One: Of the group.
- Rain of Arrows: One of her skills, Thousand Shot.
An elegant young alchemist that Firis meets on her journey. Ilmeria seems full of herself and has a high opinion of her own talents. However, she turns out to be not only skilled but hardworking as well. She develops both a friendship and a rivalry with Firis, enjoying her company but unwilling to "lose" to her. Ilmeria has a bit of a pedigree when it comes to alchemy...which turns out to be more of a headache than a boon.
- Friendly Rivalry: She is simultaneously Firis' biggest rival and her best friend.
- Girls Love Stuffed Animals: Although she can't bring herself to admit it at first, she becomes enamored with a plush toy of a plump chick she finds in Reisenberg. It takes Firis gifting it to her as an apology after they have a fight for Il to admit that she likes stuffed animals.
- Playing with Fire: Her unique skills are fire-based.
- "Well Done, Son!" Guy: She really wants her family's approval, and tries her best to live up to their high standards as the best alchemists in the land. After being beaten by Sophie and possibly Firis on the exam, she feels as if she's disappointed her parents due to not getting first place, but she finally earns their respect by choosing to open her own atelier.
DrossellThe daughter of Fritz Weissberg from Atelier Sophie. She is just as obsessed with dolls as her father, and also suffers from a tendency to get lost easily. Her dream is to write the script for the ultimate puppet show.
- An Axe to Grind: Her primary weapon is an axe.
- Boobs of Steel: Of the female party members, she's the one most focused on melee combat, and she also has the largest breasts.
- No Sense of Direction: And how! Her goal is to reunite with her father, who she lost track off after wandering off. In her introduction, she somehow makes her way back to the same spot three times in a row over a pretty long time.
- Warrior Poet: Not only is she an expert at wielding all sorts of heavy weapons such as axes, spears, and zweihanders, she's also a very talented playwright who writes the scripts to her father's puppet shows.
AngriffAlso known as "The Immortal" due to his unusually long career in a dangerous field of work, Angriff is a mercenary Firis meets and hires in a tavern in Flussheim. Although he may appear to be a miser at first, he gradually reveals his true colors during his travels with the group.
- The Alcoholic: Frequently comments on the local booze when entering a town.
- BFS: His primary weapon is a Zweihander.
- Get Rich Quick Scheme: Ropes Firis into a few of these, including asking her to alchemize a golden Puni statue and slaying a dragon.
- Hidden Depths: He seems like he might be just Dumb Muscle at first, but he's actually a quick study and is about a lot more than just fighting.
- Mistaken for Pedophile: At one point, he expresses an interest in Firis's alchemy exam, admitting he never went to school and he doesn't know what an exam's like. As his questions continue, Liane wonders if he's suddenly interested in exams perhaps because he's interested in children in "that way." He is rightly offended by this and she admits that she probably went too far. As described just below, his motives are indeed pure.
- Only in It for the Money: Suverted. Although he is constantly looking for ways to make money, his true motive is to use his accumulated wealth to build a school and ensure that children aren't forced to live dangerous lives like his.
- Red Baron: He is mostly known as "The Immortal", since mercenaries tend to live short lives.
RevyA man who seeks power by collecting ancient artifacts. He joins Firis after she helps him by fixing a key relic with her alchemy. Despite his cold and frightening exterior, he is actually a reliable person who loves to help with housework and cooking.
- Chuunibyou: His appearance, mannerism, and speech patterns are textbook Evil Eye chuuni. For example, one event has him invent overly long and dramatic names for common items. By the time of Atelier Lydie And Suelle, this way of speaking has rubbed off onto Firis.
- Real Men Cook: He's an amazing cook, and also a skilled swordsman.
KaldKald is a member of the Guiding Tribe, a clan which has taken upon the duty of recording the world's history from the shadows. During his travels with Firis, he becomes curious about his own clan's history, which is the one thing they do not record, and tries to find answers regarding his ancestors.
OskarA returning character from Atelier Sophie: The Alchemist of the Mysterious Book, Oskar is as obsessed with plants as ever. Sometime in between the two games, he's managed to lose some weight, while also befriending a new plant named Chelsea.
- An Axe to Grind: Due to the more generalized weapons of this game, Oskar falls under the class of axe-users.
- Formerly Fat: Apparently, Oskar can burn fat very easily, explaining the shocking difference in appearance between this game and the previous. Liane is quite jealous of this ability.
- Shovel Strike: It's classified as an axe, but Oskar's ultimate weapon, unlocked by finishing his quest line, is a shovel.
SophieAn alchemist from a small town called Kirchen Bell, who travels the world in search of ways to further increase her knowledge of alchemy. She becomes Firis' teacher after her quest leads her to Ertona, but despite her great knowledge of alchemy, she still doesn't have her certificate, and sets out to earn one at the same time as Firis.
- Hero of Another Story: Implied by her suddenly having something very important to do in the second town. Of course, she's also had her own story before ever meeting Firis.
PlachtaPreviously a living book, Plachta's soul was transferred into a doll's body by Sophie, allowing her to accompany her on her adventures.
- The Reliable One: She is much more responsible than Sophie.
TianaA traveling girl who stumbles upon Firis' tent. She grew interested in Alchemy after seeing her at work, but seems to have trouble understanding that she's not a witch.
- Courier: Her jobs seems to be making deliveries.