Christa is quite short and has long blonde hair with a center bang, large blue eyes, and a heart-shaped face. She usually wears a pink cardigan over her white button down with a blue bow and a blue skirt underneath. Christa is noted for being very pretty; this, coupled with her kindness, sometimes causes her classmates to wonder if she is a goddess or an angel.
Christa is seen to be one of the nicest people at Titan Junior High, being very sweet and apologetic. This causes many male classmates to fall in love with her, especially Reiner Braun. She is very loyal to Ymir.
Christa rushes to school with toast in her mouth, but crashes into Eren Jaeger by accident. Ymir recovers her and scowls back at Eren. Eren apologizes to Christa by giving her money, only to be revealed that he only gave ten yen. Along with the others, Christa and Ymir accidentally rush into the Titans' side of the school. Upon entering the Titan class 1-4, she is attacked by falling stationery but Ymir protects her and runs out the classroom. She and the group are found by Hannes and they are escorted to their actual class. There, Christa introduces herself and is later asked to go to the courtyard for the entrance ceremony. She is among the students trying to protect their lunch from being stolen by the Titans.
Christa finds her friends complaining about their clubs and she joins in, discussing her activities in the brass club. She follows her friends to locate the Attack Junior High Scout Regiment, where she meets odd upperclassmen who welcome her into the club, despite being in a different one already.
Along with Ymir, Christa confronts Annie and asks her about her favorite lunch. As Annie reluctantly answered Mozuku seaweed instead of cheeseburgers, Christa notes her maturity in her food choices.
With the dodgeball match the next day, Christa participates on Annie's team. When the ball hits her, Reiner rushes to her side unluckily for him Ymir is on guard. She trips Reiner and catches the ball, holding as the entitled savior of Christa. Christa thanks her, as Ymir follows up a proposal. On lunchtime, Christa and the other team members offer their Mozuku lunches to Annie.
Christa is upset with Ymir for hitting her with a xylophone mallet in the Brass Club.
After receiving her test results, Christa looks at them with a content expression.
Christa and her classmates are stuck cleaning after irking the upperclassmen. As she climbs a ladder, she tumbles and begins to fall. Reiner stands behind her ready to catch her, until Ymir intercepts and kicks him in the face, catching Christa instead. Ymir tells Christa to marry her once they were finished cleaning.
Later in the school's Sports Day, Christa changes into her cheerleading uniform, smiting Ymir and Reiner. She encourages her shy fellow cheerleader, Annie, to step forward and cheer for their team.
When the upperclassmen plan a sudden "Test of Courage" event at night, Christa is assigned to Ymir's group. In the bathroom, they hear one of the school's Seven Wonders, a voice coming from one of the stalls after Ymir dares knocking it three times. They run out of the bathroom, and Christa is separated from her group.
Christa cries outside, when a ghost girl tries to scare her, she stops after she sees how upset Christa is, and instead she asks her what is wrong. Christa tells the ghost about how she got separated from her friends. The ghost tells Christa that she should not walk around late at night at risk of becoming like the ghost. Christa says she would not mind becoming like the ghost, and the ghost is shocked by this, hugging and telling Christa that she can stay as she is.
Ymir then runs outside where Christa is sitting, and the two are reunited. At the gym, everyone starts running around as ghosts and a giant cannon appear chasing after them. It is later revealed that the event is a prank played by the upperclassmen.
Reiner approaches and asks Christa if she would like to go to the summer festival with him. When she agrees, Ymir tells her that she had promised to go with her, and Christa says it will be more fun if they all go together. At the festival, Reiner tries to say how cute Christa looks in her kimono, but Ymir kicks him to the side and compliments Christa herself. Christa later participates in die-cutting with her friends, and watches as more festival fireworks are set into the sky.
Following the election for a new student council president, Christa is present during the candidates' final speeches. When Reiner states his plans for holding swimming meets to increase the opportunities of physical contact between the students, as well as showcasing female students in swimsuits, Christa looks back at him in disgust, remarking how low his plan is. Reiner is shocked stiff by her reaction, to the point Bertholdt has to drag him off stage.
In the school's 104th festival, Christa and Ymir participate in their club's maid café, serving Reiner and Bertholdt omelet rice. Smitten by how Christa looks in a maid getup, Reiner thinks to himself that he wants to marry her. An irritated Ymir spoils Reiner's meal, however he eats it regardless, then asks Christa for another one. When Ymir attempts to spoil it again, Christa stops her.
When the teachers get in the way of Eren trying to head to the Titans' building to retrieve his cheeseburgers, Christa headbutts one of them. She later watches Ilse Langnar's broadcast of Eren and the others venturing into the principal's office, and cheers once Eren manages to retrieve a chee-burg.
- Ymir - Christa is very loyal to Ymir, often sticking to her side. She enjoys Ymir's company disregarding Ymir's hostility towards other people, as Christa understands that Ymir is trying in her own way to protect her. What Christa is not aware of is that Ymir hoards off boys from ever trying to make moves on her.
- Reiner Braun - He is one of her few classmates that have a crush on her. Christa's attention is not diverted to him at all in that way - in fact, she merely views him as a classmate.