Satie is a young German woman who’s still getting used to living on her own with her longtime boyfriend/childhood friend, Fabel. She’s always been remembered smiling and happy, never crying, especially not when she can’t feel pain(she has CIPA). Working as an underling to Otthild’s wealthy mother, alongside Fabel, she often investigates and intervenes with those who may pose a threat. When she meets Carambola, she sees her as an asset towards justice.

Even if there's a handful of people who have taken care of her up to now, Satie is a natural leader and hands on person, always eager to do things without a fear. Many look up to her for her go-getter personality and that made her a pretty good student council president when she was a student. She has a tendency to try doing things herself when unsupervised, so sometimes it's good for her and sometimes it's not a good idea. Joining the student council was something she really did on a whim for example. She will also get hurt when doing something alone like cooking or building furniture, but her not noticing the injuries or heat is dangerous given her condition. Satie can be airheaded sometimes in regards to others' feelings. She doesn't show much worry since she downplays a lot of problems as just temporary. She is oblivious to romantic feelings as well so Fabel had to reiterate it a couple times for her to realize he liked her more than as a friend. While she doesn't feel things like butterflies or blush, they both know the other is special to them.

Satie was born to a mother who works as a professional portrait painter, and a father who worked as a classical music composer. Both were renowned for their contributions to the world, and their daughter grew up being an admirable person as well. Their charisma and strong wills shone through her smile, but even so she also had a medical condition that neither of her parents had in their immediate family. Since she was born, Satie has had a congential sensitivity to pain and anhydrosis(CIPA). Her infancy and childhood was full of doctor trips for all kinds of injuries. Unlike others who learned not to repeat things that hurt them, she faced danger multiple times by accidentally touching hot things, sharp things, and sometimes her body temperature would rise to dangerous levels because she physically couldn't sweat alongside not feeling pain. Even then, she was a kid who smiled and looked energetic. As she grew up and went to school, she even had Fabel at her side considering their families were close. As kids, Satie didn't hold herself back whether it worried others or not, but whenever Fabel was with her she did behave. The two were very good friends, in fact getting into trouble together occasionally, but it was always fun and memorable. Frankly their parents expected them to become a couple in the future, at least Fabel's crush was an obvious one, but it took Satie many years to notice how blatantly he'd confessed a few times. Perhaps because she was always going with the flow of life and always looked towards the future, she didn't slow down to notice things like his feelings in the past or present. And as she grew up needing to go to middle school, her mother insisted she go to the same school she once went to. If she could dorm there, someone would still be able to check on her. Moving to Sauzieu, Germany, Satie embarked for her remaining school years at a new school.

During her middle school and high school years, Satie presented herself as a self sufficient and careful person so her family didn't frequently contact teachers on how she was doing. She didn't want to be worried over so much when most of the time she could manage on her own. Fabel didn't pester her about it even if he wondered how she was at an all girls school. The two dated and communicated, but they went to different schools after elementary. To busy herself, Satie joined the student council. She wasn't that academically ambitous, but others relied on her since she gave the impression of a cool older sister, that charisma noted by teachers as the making of a good president. She went along with it and had fun doing so, training Alfajor under her wing until she was ready to succeed her once Satie graduated. And so, when she was out of school, Satie easily moved in with Fabel in Sauzieu. The two applied for the same bodyguard job for a rich woman, but given that they could be good at other things, they were eventually enlisted in an underground group the lady had.

When Satie's family checks in, she always says that her and Fabel are doing well, working in a private company. It's partially correct, but she won't say what they really do behind the scenes. After all, Satie is good at infiltrating buidlings to vandalize them, while Fabel walks around with a sniper gun to damage things important to the elite; statues, homes, whatever makes them feel so prideful. Simply put, it's what they're used to, yet another figure enlists the help of the two. Satie had heard of Carambola, a solo hero saving many in the town when needed. Thinking she'd run into her, she'd really met another magical girl named Porzellan, one who looked uncanny to a late child star named Hania. Her image faded to others over time, but Satie recalls being a fan of her. With Porzellan wanting to stir trouble in her elite father's life, Satie was quick to offer help however she could, Fabel going along with it. During the day, Porzellan started to live with them, at times leaving her sibling as a vessel to use Satie instead. To Satie, the two siblings are justified in their schemes, but if Carambola catches wind of it, she may not agree with the danger that comes with it. Even Fabel worries that Satie is avidly getting in harms way, so he won't allow her to fight on her own.

"Fabel, cmon... aren't you worrying too much? Ah, I fell." A very good looking, but very strange couple. Satie is used to Fabel doing things for her but she likes to watch and learn, while Fabel likewise thinks Satie is very admirable and strong minded. They're so casual they're more platonic in actions than romantic. Satie can't really blush, but Fabel blushes so hard that's more than enough, especially as he's more romantically smitten over anything Satie does.

"What do you want to do today, Hania? Of course you can pick! You've always got interesting ideas, you know?" Porzellan is a former child star that Satie once looked up to, until she suddenly passed away. Satie is fascinated by her and Carambola's existences, vowing with Fabel to do what Porzellan says since she's a really good asset for justice. Satie does wonder if it's possible for just anyone to end up like them when they pass, but Satie is a simple minded person herself who'd be satisfied at the end of her life, so no. Porzellan finds Satie strange yet interesting too.

"Hm? If you want any help, I don't mind helping out. Who are you taking down? No one, really? Well, that's fine too. Oh, no, no-- I wasn't going to hurt anyone! Haha!" Carambola is another magical girl Satie has run into, a more open and immediately sweet person than Porzellan, too good hearted that she isn't as gritty in nature with particular grudges. Her goals are more lighthearted, to simply help her family, which Satie respects. Carambola finds Satie approachable but doesn't like the idea of her getting involved in dangerous things, seeing how Fabel frets over her. Occasionally Carambola asks Satie for the favor of using her as a vessel for casual matters when Peppin is busy.