Born and raised in the Shiganshina District, he grew up alongside Eren and Mikasa with a similar fascination for the world beyond the wall. Despite his concerns over his physical strength, he joined the 104th Cadet Corps and endured three years of harsh training. Although he did not graduate in the top percantile, he earned top marks in his coursework.
Though he is shameful of always being protected by his childhood friends due to his timidity and shyness, his excellent analytical ability and good judgement shows his extraordinary talent as an intellectual solder.