Sweet Summer! Titan Junior High School (甘夏！巨人中学校 Amanatsu! Kyojin Chūgakkō?) is the 9th episode of the 1st season and the 9th episode overall of the Attack on Titan: Junior High, produced by Production I.G.
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.
During class, Bertholdt's odd sleeping position attracts the attention of his classmates. Reiner calls out for him, wondering how he can sleep that way. Jean remarks his artistic pose, while Conny bets the weather being sunny for tomorrow based on it. Reiner wakes him up and he falls off his desk. Reiner tells him that he has an important favor to ask; he is thinking of asking out Christa for the summer festival. Clueless, Bertholdt wishes him good luck, but Reiner says that he is coming too. Bertholdt is confused as to why, and Reiner tells him that he feels embarrassed going alone with Christa, as much as he likes that idea.
Glancing at Annie, Reiner then proposes for Bertholdt to invite someone out too, and names her. Blushing with his face all red, he quickly dismisses it and says there is not anyone he wants to ask, with Reiner remarking how of an open book Bertholdt is. While Ymir and Christa are conversing, Reiner comes and asks Christa if she would like to go to the summer festival with him and Bertholdt. Christa quickly agrees, much to his surprise. Ymir then tells her that she had promised to go with her, and Christa says it will be more fun if they all go together and starts thinking about who they should invite next. Annoyed, Ymir tells Bertholdt to say something, but notices his mind is somewhere else; he is looking at Annie. She then approaches and tells him that she would be busy staying with Christa at the festival so he should invite someone too, and again, Annie is named. Bertholdt reacts the same way he did when Reiner mentioned Annie earlier.
Reiner calls out for Annie this time and tells her that Bertholdt wants to talk to her. He panics and asks Reiner if they are really going to do it right there, right now, and Reiner says the time has come. Bertholdt stutters, but manages to ask Annie if she wants to go with them to the festival. Annie says she is not interested just as Eren and the rest of the class arrive and hear them. Eren shouts in excitement, that he will be going and Mikasa says that she too will be going if Eren is; Armin says it sounds fun; Sasha lists the festival food she will be eating and Jean says he will be teaching them how to enjoy a festival. Annie yields, and Christa is happy about everyone going. However, Ymir, Reiner, and Bertholdt are disappointed that the entire class is also going.
A while later, on the school's rooftop, Reiner says he is glad Bertholdt was able to invite Annie, despite a bunch of unwanted people going with them. Seeing that Bertholdt is still not admitting it, Reiner tells him they should put an end to this with Bertholdt telling Annie how he feels about her at the festival, but he still denies it. Reiner tells him that he stares at her too much, to the point that anyone can tell, with Ymir saying the same, and calling him "Mr. Stare-thol." He then cowers in embarrassment, but Reiner tells him this is his chance to get close to her. Ymir then mentions the others getting in the way, but Reiner says he has a plan, as Bertholdt is thinking to himself that all he wants is to be by Annie's side.
The summer festival day is here. Reiner stands outside with Bertholdt, and the former explains his plan. Operation 1; all Bertholdt has to do is compliment Annie by calling her cute. Ymir, Christa, and Annie then arrive. As Reiner tries to say how cute Christa looks in her kimono, Ymir kicks him to the side and compliments Christa herself. She then tells Bertholdt to say something to Annie and compliment her kimono. He stutters a little, before complimenting a knot on her geta strap instead, to Reiner and Ymir's disappointment. The rest of the class arrives, and Sasha says Annie looks pretty in her kimono, and she replies that her father got it for her. Eren, excited where to go first, is reminded by Mikasa that his mother told him to use his allowance carefully. Reiner continues with his plan. Operation 2; Bertholdt showing Annie his manly side by playing a shooting game. Reiner tells him a shooting game is the best way to show one's manliness at a festival. Arriving at the stall, its owner welcomes them and introduces himself as Ness and his pet hamster, Charrette. He warns them that she likes to pull people's hair, before she starts pulling at his bandana.
Mikasa easily wins at the game from her first try, and chooses to gift Eren her prize, the Big Pork Fillet Cutlet, saying he looked like he wanted it, and he asks her what kind of look is it. Seeing this, a determined Annie tries the game and wins on her first try as well. Looking back at Mikasa, a sense of rivalry sparks and they both demand the stall owner to give them another try. They both win every prize in the stall, and the owner begs them not to run him out of business. Shocked at their performance, Reiner then decides that a winning game is not the best way after all, and assures Bertholdt that his plan still has a trump card.
Feeling hot, Bertholdt asks the group if they want shaved ice, and Sasha jumps at the idea and rushes ahead with Conny to buy some. Reiner tries to stop them, but fails, and decides to continue with the plan. Operation 3; Bertholdt protects Annie from staining her kimono. The plan is as follows: Ymir buys shaved ice and as she is about to "accidentally" spill it on Annie, Bertholdt comes and shields her. However, the wrong people went to buy the shaved ice, and Ymir believes Sasha and Conny got lost.
Suddenly, Bertholdt tells Reiner to forget about the plan, and that it is not nice to put Annie in danger just for his sake. Reiner tries to explain that they are trying to help him, just then, Conny and Sasha arrive with the shaved ice. Sasha blames Conny for trying to take a shortcut and Jean complains that the ice had melted since they took so long getting back. Sasha says that she will take it if he does not want it, and as she is reaching for the cup from Jean, Ymir sneaks behind them and pushes Jean's arm, with the cup heading towards Annie. Bertholdt yells for her to watch out, and then shields her as the ice is spilled on him instead, just as Reiner had planned. Annie asks if Bertholdt is okay, and he says he will go wash his clothes.
Pouring water on himself, Bertholdt regrets putting Annie in that situation. Nearby, a man calls for visitors to come and try die-cutting, catching Bertholdt's attention. As the others split up and start looking for him, Annie finds where Bertholdt is. She stands behind him as he is die-cutting, and the man praises his skill, saying he would go bankrupt if he keeps that pace. He hands him two masks as a prize, to Bertholdt's confusion. The man says it is for him and his girlfriend behind him. Seeing Annie, Bertholdt blushingly denies the relation.
Sitting nearby on a bench, Annie tells him that the others are supposed to meet up here once he is found. He apologizes for causing them trouble. Annie says he had always liked die-cutting, so she had a hunch he would be there, to his amazement that she remembered. She says she has not been to a summer festival in a long time, and Bertholdt apologizes for asking her to come along so suddenly, and hopes she is having fun. Annie says that she does not like crowded places, making Bertholdt apologize again earnestly. However, Annie tells him that it might have been good he asked her to come along, but says it is not because she wanted to come with him, rather she feels at ease with him and can be herself, saying he is convenient to have around. Bertholdt tells her that she does not even sound like a friend, with Annie realizing what she said did sound weird, and tells him that maybe he is like "air" to her, shocking him even more.
She then starts laughing as the others arrive behind them. Sasha tries to call out for them, but Ymir and Reiner silence her. Annie apologizes, and they both speak at the same time, interrupting each other. The others hiding behind bushes watch eagerly as Bertholdt asks Annie something as fireworks are set off, and she replies "okay." The others fall from the bushes and reveal themselves, with Reiner and Ymir congratulating Bertholdt, thinking he had finally asked Annie out. He then tells them they will go do die-cutting, to Reiner and Ymir's confusion. Back at the die-cutting table, the class sits and participates, except for Ymir and Reiner, who let out a sigh in disappointment at the fact Annie had actually said okay to doing die-cutting with Bertholdt. The class then watches in enjoyment as more festival fireworks are set into the sky.