Jean Kirstein

The Attack on Titan manga and anime series feature an extensive cast of fictional characters created by Hajime Isayama. The story is set in a world where humanity lives in cities surrounded by enormous walls; a defense against the Titans, gigantic humanoids that eat humans seemingly without reason. The story initially centers on Eren Yeager with his childhood friends Mikasa Ackerman and Armin Arlert, who join the military to fight the Titans after their home town is invaded and Eren's mother is eaten. They are part of the 104th Training Corps, whose graduates assume different positions in the Military, including the Garrison Regiment, the Survey Corps and the Military Police Brigade.

Paradis (パラディ, Paradi) is a massive island on which the three Walls are located. It became the last territory of Eldia (エルディア, Erudia) after the Great Titan War, and hosts refugees mainly consist of ethnic Eldians.

The military within the walls of Paradis Island is divided into three divisions: the Survey Corps, the Garrison Regiment and the Military Police Brigade, all under the supreme command of Darius Zackly. Applicants into the Military are first required to enter the Training Corps, overseen by Keith Shadis, after which they are allowed to join one of the three divisions according to their grades.

The Training Corps (訓練兵団, Kunren Heidan) is the branch of the military dedicated to training and educating new recruits to become members of the three main military branches. Only the top ten graduates can apply to the Military Police Brigade, giving them the privilege of living in the Inner District. The other graduates can only choose between joining the Survey Corps or the Garrison Regiment.

The 104th Training Corps (第104期訓練兵団, Dai-hyakuyon-ki Kunren Heidan, alt. "104th Cadet Corps") is the only graduating class introduced in the series and the southern division contains nearly all of the central characters. It was active during the years 847 through 850 when the remaining recruits graduated. In the manga, the top ten cadets were listed by their individual ranks,^[ch. 2] but in the anime, the top ten are recognized as a group. Along with Eren, Mikasa, Armin, there are the following members:

...
Wikipedia