Hannes is a character from the Attack on Titan anime, specifically appearing as a member of the Garrison Regiment. He is first introduced as a stationed soldier in the Shiganshina District, where he is often found drinking and passing the time, a habit that reflects his generally laid-back and carefree attitude toward his duty. Despite this lackadaisical approach to his job, Hannes is a deeply caring individual who shares a long-standing friendship with the Yeager family. This personal connection, particularly his gratitude toward Eren's father, Grisha, for saving his wife from an epidemic, creates a powerful sense of indebtedness that motivates many of his later actions.

Hannes's life and personality are defined by a single, traumatic event during the fall of Wall Maria. When the Colossal Titan breaches the wall, Hannes rushes to the Yeager household to find Eren and Mikasa desperately trying to free Eren's mother, Carla, from the rubble. Upon arriving, he prepares to fight the Titan approaching them but is overcome by sheer terror. Overwhelmed by fear for his own life, he is forced to grab a struggling Eren and Mikasa and flee, abandoning Carla to her fate. This moment of perceived cowardice becomes an immense source of guilt and regret that haunts him for the next five years. He is deeply ashamed of his lack of courage, and this failure reshapes his character, transforming him from a jovial drunkard into a more dutiful and serious soldier. He eventually rises to the rank of Captain within the Garrison's Engineering Corps in the Trost District.

Driven by the need to atone for past failures and repay his debt to Grisha, Hannes is fiercely protective of Eren and Mikasa. When he reunites with the now-teenaged duo after their graduation, he takes the opportunity to apologize for his past actions. Eren, having matured, holds no grudge against him, recognizing the terror that Titans inspire. This reconciliation strengthens Hannes's resolve. When Eren is later abducted by the Titan shifters Reiner and Bertholdt, Hannes is determined to join the rescue mission, declaring that he would rather die than fail to bring Eren back, as he feels that peaceful days cannot return otherwise.

The culmination of Hannes's personal redemption arc occurs during the battle to rescue Eren. As the soldiers retreat, the same Titan that killed Carla, known as the Smiling Titan, appears and attacks Eren and Mikasa. Seeing this as the moment he has been waiting for, Hannes bravely engages the creature, vowing to kill it this time and make up for his past mistake. He fights with a newfound courage, but his abilities are ultimately no match for the Titan. In a tragic turn, he is caught and devoured while protecting the children he had once failed. His death serves as a profound emotional catalyst for Eren, reinforcing the cyclical nature of loss and the constant sacrifice required in their fight for survival.

In terms of abilities, Hannes is a competent and experienced soldier of the Garrison, though his official stats indicate his skills are more focused on coordination and action rather than exceptional combat prowess. He is described as having high degrees of coordination and mobility, making him a reliable field leader and supportive figure, but his direct combat capabilities are modest compared to the Scout Regiment's elite or the Titan shifters. His primary strengths lie in his loyalty, his determination to protect those he cares about, and his ultimate willingness to sacrifice himself to fulfill a promise and ease the guilt of a past sin.