|I liked those days...if Eren were here, he might call them a time of false peace...but being a good-for-nothing, drunk soldier was enough for me.|
|— Hannes longs for simpler times|
Hannes was a tall, well-built man with short blond hair, a thin dark mustache. He wore the typical uniform of the Garrison Regiment along with a v-neck shirt underneath.
Hannes was a very kind, good-natured man, but he always drank irresponsibly. Although somewhat cowardly, he was determined to die if it meant freeing Eren from his captors. He was greatly ashamed of his lack of courage five years ago, and waited to encounter the Titan who killed Eren's mother, Carla Yeager, again, in order to slay it and make up for his past mistakes.
Hannes cared deeply for Eren and Mikasa and looked out for them after Carla was eaten. He ultimately gave his life to protect them.
When Keith Shadis found a civilian beyond Wall Maria, the man was imprisoned for leaving the Walls without permission, and Hannes was stationed at his jail cell to watch him. Drunk while on duty, Hannes was perplexed that anyone besides the Survey Corps would be "stupid" enough to leave the Walls, suggesting instead that the man may have left the Walls while intoxicated, explaining his memory loss.
The man, Grisha Yeager, soon began working as a doctor in Shiganshina District. When a plague broke out in the district, Hannes' wife was among the afflicted who were saved when Grisha developed a cure; a debt to the Yeagers he became determined to repay. Hannes was also present at Grisha and Carla's wedding later on.
While on duty, Hannes and his companions keep themselves entertained by drinking and playing card games. Their fun is interrupted by Eren Yeager, who criticizes them for not taking their job seriously and demands to know what they would do if Wall Maria was breached by the Titans while they were drunk. Hannes nonchalantly assures the boy that the Walls will never be breached and argues that Eren should be happy that the Garrison has nothing to do, as the day that they have their work cut out for them will be the day that Titans really do break in and threaten the peace of the Walls. Eren retorts that living inside the Walls their entire lives makes them no more than caged animals, causing Hannes to worry that the boy is considering joining the Survey Corps.
During the fall of Shiganshina and subsequent Titan invasion, Hannes is informed in the midst of the chaos by Armin Arlert that Eren and Mikasa Ackerman went to their house to see if it has been destroyed and may be in danger. Going to their house, Hannes arrives to find them desperately trying to free Eren's mother Carla from underneath the rubble of the house. Hannes initially ignores Carla's pleas to flee with the children in favor of engaging a nearby Titan, only to find himself frozen in fear at the sight of it. Unable to bring himself to fight the Titan, Hannes flees with Eren and Mikasa, leaving Carla behind.
After they have escaped, Eren begins punching Hannes repeatedly, insisting that he would have been able to save his mother if Hannes had given him more time. Hannes throws him to the ground, telling Eren that he would not have been able to save his mother as he was not strong enough. Enraged, Eren continues punching, but Hannes catches the boy's punch, tearfully explaining that he himself had not been able to save Carla because he lacked the courage to try. He escorts the two away from the chaos, apologizing repeatedly.
Over the next five years Hannes works diligently, steadily climbing through the ranks of the Garrison until becoming a captain.
On the night of Eren, Armin, and Mikasa's graduation from the 104th Training Corps, Hannes runs into them while going over reports with other Garrison soldiers. After trading some playful insults with them, Hannes apologizes for not being able to save Carla, lamenting that he will never get a chance to repay his debt to Grisha. He asks Eren if he can remember anything about the final time he saw his father, which prompts Eren to suffer a migraine. Hannes quickly apologizes, having forgotten how painful it is for Eren to try to remember the night of his father's disappearance.
After Trost District is attacked by the Colossus Titan and breaks down, Hannes's squad takes up positions atop Wall Rose to serve as lookouts, in case the Colossus Titan returns. As Hannes admires the harpoons that were set up to catch any Titans near the wall, his subordinate Phil expresses his fear for their comrades, reminding Hannes that Eren, Armin, and Mikasa are members of the vanguard. Hannes calmly tells Phil that he is sure all three are still alive.
As Hannes works on the cannons mounted on the wall, he sees Eren walking with Commander Pixis. He is relieved that Eren is okay, but quickly becomes annoyed when the youth simply signals for him to focus on his work. Though he is upset that Eren would treat a superior officer in such a callous way, Hannes deduces from Eren's demeanor that Mikasa and Armin are also alright, and begins to wonder why Eren is walking with the commander as they leave.
Hannes appears once more apparently giving a report to Dot Pixis when a Garrison member bursts in and informs them that Wall Rose has been breached. Hannes's unit is assigned to patrol Wall Rose to find the breach. As they patrol, Hannes is bewildered by the fact that they have yet to encounter any Titans, noting that all previous breaches have only occurred after a large amount of Titans have been gathered together at the source of the breach.
Hannes's unit searches through the night, but does not find any breach in the wall. They double back, and meet up with Survey Corps to relay their findings. As the corps soldiers depart, Hannes advises Eren, Armin, and Mikasa to keep their guards up, before departing with his unit as well.
Hannes is almost immediately drawn back to the wall by the appearance of the Colossus Titan. Although he is shocked to see it again, he is more concerned with finding Eren and making sure that he is safe. Historia Reiss points him to where Eren is engaged with the Armored Titan. Just as Hannes gets his first glimpse of Eren's Titan form, the Colossus Titan pushes itself off the side of Wall Rose, allowing itself to fall on top of Eren and the Armored Titan. In the resulting explosion, the two enemy Titans are able to escape with Eren.
In the aftermath, Hannes is one of the few commanding officers left unharmed by the impact of the Colossus Titan's fall. Once Mikasa and Armin wake up, Hannes brings them food rations, and sits down with them to eat. He tries to lighten the mood by bringing up the fact that the two are still having to fix situations caused by Eren. He fondly remembers the way that Eren would constantly throw himself into fights and never admit defeat to anyone, pointing out that all Eren really has to do at the moment is slow down the two boys who kidnapped him until they can go to rescue him. He rounds out his speech by informing Mikasa and Armin that he will be joining the mission to rescue Eren, as he feels that he will never be able to go back to the peaceful days he enjoyed in Shiganshina if Eren is not recovered.
When they arrive at the Titan Forest, Hannes commands Phil to watch their horses as he enters the forest, and orders the rest of his unit to search for the enemy and report back if they find them. Although they find the traitors in the forest, they are not able to catch them. As their enemy flees out of the forest, Hannes orders his unit to continue their pursuit on horseback. He swears that he will rescue Eren, even if it costs him his life.
Catching up to the Armored Titan, Hannes joins the rest of the soldiers in attempting to attack it, to no avail. He falls back as the 104th graduates attempt to reason with their former comrades, but orders them to fall back as well when he sees Erwin leading a horde of Titans directly towards Reiner. As the Armored Titan attempts to force its way through the Titan horde, Hannes joins the rest of the soldiers in a full-scale attack on it.
Erwin finally manages to take back Eren, and the military forces begin to retreat. However, their path is blocked by the Armored Titan, who begins throwing Titans to block the escape route. Eren and Mikasa are knocked off of their horse, and Hannes is forced to intervene to save them from a nearby Titan. Recognizing the Titan to be the same one that devoured Carla, Hannes is thrilled at the chance to avenge her death, and brazenly begins to engage it. However, his efforts are ultimately in vain and the two children he once rescued are forced to watch as he is bitten in half and devoured by the Titan.
In the aftermath of the battle, Eren, Mikasa, and Armin grieve his death while they recall their childhood spent with him.
The night before the reconquest of Wall Maria, Eren, Armin, and Mikasa mistake an old Garrison soldier for Hannes, which makes them think about the past.
Hannes's statistics as of year 850:
- Eren Yeager - Hannes knew Eren for most, if not all, of Eren's childhood, as he was friends with his father, Grisha Yeager, and they both lived in Shiganshina prior to its fall in 845. Eren was often infuriated by Hannes' laid-back attitude towards his job, but Hannes was more amused than offended by his attitude. Hannes placed tremendous faith in Eren's determination. When Eren was abducted by Reiner and Bertolt, Hannes was the one to reassure Mikasa and Armin that Eren would hold out until the Survey Corps arrived.
- Mikasa Ackerman - Hannes met Mikasa after she was taken in by the Yeager family. He referred to her as one of the best fighters he had ever seen and remembered her for fending off neighborhood bullies with ease. When Eren was abducted by Reiner and Bertolt, Hannes reassured Mikasa that Eren would be fine, stating that the days he spent with the three of them in Shiganshina were among the best in his life, and that he would not stop fighting until he brought them back.
- Armin Arlert - Hannes and Armin both lived in Shiganshina prior to its fall in 845. Hannes has described Armin as a genius and believed in him, along with Eren and Mikasa, to be capable of surviving through dangerous situations. When Eren was abducted by Reiner and Bertolt, Hannes reassured Armin that Eren would be back with them soon. Hannes would not stop fighting until the three of them were together as they had been in the "good old days."
- Grisha Yeager - Hannes met Grisha soon after the latter first set foot in the Walls. Later on, Hannes became very grateful towards Grisha for developing a cure that saved his wife, and remained on friendly terms with the Yeager family ever since.
- Carla Yeager - Hannes and Carla were close persons before the fall of Shiganshina District. He tried to save her from a Titan after the Colossus Titan breached wall Maria, but got scared and saved Eren and Mikasa at her request instead. Five years later, Hannes still regretted not being able to save Carla and was ultimately killed by the same Titan as he tried to avenge her.
- Keith Shadis - Hannes seemed to have known Shadis for a long time, as he spoke with him back when Shadis first found Grisha. The two exchanged slight banter and discussed what do do about Grisha.
- Hannes ranked forty-sixth in the Second Character Popularity Poll.
- The name "Hannes" is a diminutive of the German name "Johannes" which is itself a German variant of the name "John," meaning "God has been gracious."