Franz had a large build with shaved black hair. He wore the standard Training Corps uniform.
Franz was a good-natured young man, only wanting everyone to get along. He was not one to get upset or anger others. He was also protective of those he was close to, such as Hannah Diamant, who he vowed to shield from the Titan breach during the battle of Trost District.
On the 104th Training Corps' last night together as trainees, a fight between Eren Yeager and Jean Kirstein breaks out which Franz and Mikasa have to break up. Later that night, Franz helps carry Eren to his bed after he passes out.
The next day, Franz is walking through Trost District with Hannah and Eren. He and Hannah begin chatting, optimistic that things are looking up for humanity. Angered, Eren begins yelling at them and embarrasses them by calling them a couple.
After the Colossus Titan's attack on Trost, Hannah is frantic at the situation they are in. Franz tries to ease her fears, vowing to look after her no matter what.
Later, Armin comes across Hannah frantically trying to revive Franz's mutilated body with CPR.
- Franz's name is remarkably similar to Franz Kafka, a Czech writer considered to be one of the most influential authors of the 20th century. Franz's lover, Hannah Diamant, shares the same last name as Dora Diamant, who was the lover of Franz Kafka during the final year of his life.
- Franz shares a birthday with Mr. Arlert.