After the race of the last day, Hange and the other upperclassmen challenge Eren's class to a test of courage. That night they arrive at school, where Hange and Levi explain the rules: they must visit the art, music, and science rooms and write their names on the blackboard. The class splits into two groups and head out, encountering various ghostly apparitions said to be the "Seven Wonders of Attack Junior High"; there is a rumor that anyone who sees all seven will be cursed with misfortune. Finally reaching the gym, they find that the ghosts were, in fact, a prank orchestrated by the upperclassmen. Erwin Smith, the club's advisor, reveals that one spirit, the woman with black hair whom Christa encountered, was, in fact, a real ghost.

Bertholdt asks out Annie to the summer festival with Reiner, Christa, and Ymir. She is not interested but is forced to join in after her classmates all decide to go. On the rooftop, Reiner urges Bertholdt to tell Annie how he really feels about her. On the day of the summer festival, Reiner puts together three operations in plan to get Annie to fall in love with Bertholdt, but fails. In the third operation, shaved ice is almost spilled on Annie but Bertholdt rushes towards her in time, only to get himself soaked. After he washes himself, he heads towards a die-cutting stall out of interest while the group tries desperately to find him. Only Annie seems to know where he is and the owner of the die-cutting stall gives Bertholdt two masks thinking that Bertholdt and Annie are dating. Bertholdt blushes hard and tells him otherwise. The two sit on a bench at the area where the entire group is supposed to meet. Sasha is about to call out to them but Reiner and Ymir hold her back. In the end, Bertholdt seems to confess his feelings towards Annie under the cover of fireworks, and she replies with a "yes." Just then, the group eavesdropping fall out of the bushes. Reiner and Ymir congratulate Bertholdt and Annie. Bertholdt actually asked Annie to go die-cutting with him, much to Reiner and Ymir's disappointment. While they are die-cutting, fireworks appear in the sky and everyone is in awe.

Following the events of the 104th school festival, Eren vows to get their cheeseburgers back from the Titans, defying the teachers and heading to the Titans' building. Finally making their way to the principal's office, where they believe the cheeseburgers to be located, they find a gigantic key in the center of a small city. As the rest of the class fights to hold off the attacking Titans, Eren carries the key to the keyhole and unlocks it. Inside, they find themselves in what is revealed to be the principal's lunch box, as the Colossal Titan lifts the lid and takes the cheeseburger stand. Enraged, Eren attacks, but is swallowed along with the stand. As his classmates look on in horror, however, the Titan spits him back out, and Eren reveals that he managed to rescue one of the burgers. As the students celebrate their first victory against the Titans, Erwin tells the other faculty that with this victory, human students now have a chance for a happy school life.