In the year 848, Eren and his fellow cadets embark on a navigation training exercise to learn how to sustain themselves in times of peace, during which he and Jean continually get at each other's throats. While traveling on foot under the cover of night, Eren apologizes to Mikasa, who is escorting his horse in addition to her own, but she insists that he save his energy so that he can seal Wall Maria. Eren is surprised to find himself shaking in anticipation. He insists that he is just shaking from the cold, but Armin reassures him that it is normal to feel scared of the Titans and reminds Eren of when he was nearly eaten during the Battle for Trost. Eren reveals that he sacrificed himself to save Armin that day because he had remembered the first time Armin told him about the outside world, which had caused him to realize just how much the Titans had taken from the humans. After these two years, they begin their first day on the training grounds in the 104th Cadet Corps as commandant Keith Sadies grills the fresh recruits as part of their "Rite of Passage." Eren restores his vow to kill all Titans, and that next time around, they will be the ones who will be devoured. [27]

Eren had been noted to be quite charismatic and had a talent for delivering impassioned speeches, often unwittingly managing to persuade the mass of his listeners to sympathize with his point of view. Even Jean Kirschtein, his bitter rival, has admitted this, as he convinced over half a dozen recruits to consider joining the Scout Regiment before the Battle of Trost. [30] Four years later, he made use of this skill consciously, as shown when he easily lifts Falco's spirits and convinces him to deliver a letter outside of Liberio, despite the fact that Eldians are usually forbidden from leaving the internment zone. [8] After waking up from a nightmare interrupted by Mikasa, they stroll through the city and Eren expresses anger at being kept like cattle within the Walls, revealing his intentions in joining the Scout Regiment. Mikasa scolds him, not taking his words seriously, and later reveals what he said to their parents. Following the incident, Marco has a conversation with Eren, stating his belief that Jean would have made a much better choice to lead the mission, to which Eren vehemently disagrees. [43] A Sudden Visitor: The Torturous Curse of Adolescence Hannes - Prior to the fall of Wall Maria, Eren was constantly frustrated by Hannes being a habitual drunkard in the line of duty. Despite not having saved Carla from the hands of the Titan, Eren bore no ill will towards him, and instead, he looked up to him with respect and understanding. After Hannes was eaten by the Smiling Titan, Eren became enraged, showing that he had a deep friendship with him. [55] During the night, the group is ambushed while they sleep. Held at gunpoint, they are unable to do anything as the thieves carry off their ODM gear and Christa Lenz. Marco Bodt suggests abandoning the mission and getting help from Sadies, but Eren convinces the group to help him chase down the thieves before they can get away. Sasha suggests using a higher vantage point to look for the bandits, and the group is able to successfully locate where the thieves are camping for the night.Soon after entering the forest, Squad Levi is set upon by a seemingly intelligent Female Titan, who is able to dispatch pursuing soldiers with ease. Seeing the soldiers perish one by one, Eren is tempted to use his Titan power to fight the Female Titan. Levi allows this choice, but recalling Levi and his squad's trust in him when he accidentally used his Titan powers, Eren decides to trust in his team instead. [39] Eren asks Mikasa why she displays so much concern for him and Mikasa, surprised, claims it is because they are family. They are joined by Jean, Armin, Conny and Sasha and the group is welcomed into the tent by the boy's family, spending the night drinking and carousing. Roughly a year later Floch allows Yelena to discreetly meet with Eren at least once during a festival in Trost. Yelena explains Zeke's plan to euthanize the Eldian race along with his plan to feed his spinal fluid to the Military's officers so that they will not be able to oppose his or Eren's movements. Yelena would later deny advising him to infiltrate Marley on his own. Eren also learns from Yelena that Zeke wishes to speak with him in regards to his true intentions to free Paradis.

Petra Rall - Among the members of the squad assigned to protect Eren, Petra seemed to be the one closest to him. She was among the least eccentric and most friendly of the members, and Eren admired her not only for her skill but for her open acceptance of him as a comrade as well. Witnessing her demise at the hands of the Female Titan was a devastating blow to him, and he remains remorseful of making the decision that led to her death. Eren and Mikasa scare off bullies harassing their neighborhood friend Armin Arlelt. Eren offers Armin a hand but Armin rejects, expressing discontent with his abilities to protect himself and admits he is weak. The three stroll through Shiganshina and settle by the riverbank, where Eren reveals his intentions of joining the Scout Regiment to Armin. When Eren speaks with Armin he tries to apologize for the way he treated him at Niccolo's restaurant, but Armin says that he should be more worried about apologizing to Mikasa. Eren asks Armin to follow him.

The day before the operation to retake Wall Maria, the soldiers have a feast in celebration. As Eren and Conny restrain Sasha to keep her from eating everything, the two reflect on how much things have changed in three months since the battle of Trost. Jean starts a fight with Eren by insulting him and their fight is eventually stopped by Levi. Eren was a young man of average height and muscular build. He had a fairly long, yet rounded face, and sizable, expressive, teal-green eyes. His eyebrows were sparse and often furrowed, making him seem troubled or annoyed. Eren's hair was short and dark brown, with his bangs falling naturally into a middle-parted, curtain-type style. His complexion also seemed somewhat tan. After his training and during his time as a soldier, he became very physically fit and muscular. After Armin convinces Annie to join them in escorting Eren out of the city, they lead her to the entrance to an underground tunnel, where she refuses to continue following them. Despite Eren's continued pleas for her to join them and prove her innocence, Annie transforms and he, Mikasa, and Armin are forced into the underground tunnel to escape from her Titan. As per the plan, Eren tries to transform but can not because of his disbelief at Annie's betrayal. As the Scout Regiment tries in vain to capture the Female Titan, Eren is reminded of the lives Annie took as the Female Titan as well as his vow to exterminate the Titans, allowing him to finally overcome his inhibitions, transform into his Titan form, and engage the Female Titan for the second time. [48]