Jean Kirstein

He lives in a constant state of defense. After prison, he doesn't trust anything that resembles stability, because for him, stability always ends up disappearing or turning into pain. So he learns to control everything: his tone of voice, the distance he keeps from people, the time he spends in each place. The less involved he is, the less he can lose.
When he meets Celine at the party, his cold reaction isn't arrogance—it's a reflex. He doesn't want any kind of commitment, because commitment means risk. And he already knows exactly how that ends for him.
But the problem is that Celine doesn't react like other people.
She doesn't run away.
Don't insist aggressively.
Don't treat it as a danger.
She just stays.
And this affects him in a way that he doesn't know how to process.
Psychologically, in this story, Jean functions like this:
He actively avoids emotional intimacy: he doesn't "have difficulty," he literally recoils when he senses an approach.
Anticipating rejection: he already expects people to leave, so he creates distance before that happens.
Constant guilt: he doesn't see himself as someone who can be "recovered"; he thinks that any closeness will contaminate the other person.
Emotional hypervigilance: he is always reading reactions, tones, micro-signals of judgment.
Denied emotional dependency: he needs connection, but denies it all the time, until he starts depending on Celine's presence without admitting it.

In the Attack on Titan universe, Jean Kirstein is described as having a very human and realistic appearance, with striking features that match her practical and somewhat sarcastic personality.

Physically, he has light brown hair, usually cut simply and slightly messy, as if he doesn't spend much time trying to style his own hair. The strands fall naturally, sometimes with a few longer strands in the front.

His eyes are one of his most expressive features: dark brown, attentive, and often with a somewhat critical look, as if he were always analyzing his surroundings or silently judging what was around him—something that matches the more direct and observant side of his personality.

His face is angular, with a well-defined jawline and features that give him a more mature appearance as the story progresses. Initially, he may seem more "ordinary," but over time he takes on a more serious and weary presence, especially after the more intense events of the narrative.

In terms of physique, Jean is tall and athletically built, with broad shoulders and a well-trained body, the result of his military training. He doesn't have an exaggerated or flashy muscular body, but he is clearly strong and resilient, with a firm and often rigid posture.

Overall, his appearance conveys exactly what he tries to hide: someone who seems controlled on the outside, but carries tension and emotional weight on the inside.