Adapted from the popular manga series of the same name, Jujutsu Kaisen follows Yuji Itadori, who accidentally stumbles upon a cursed item that wrenches him into the world of the supernatural. After swallowing the item, he enrolls in the Tokyo Metropolitan Jujutsu Technical High School, for Jujutsu sorcerers, and trains to fight Curses, evil beings created by negative human emotion. Released in 2020, the anime series garnered much praise as a stellar shonen work. Many fans were particularly enraptured by the friendship between Yuji and another Jujutsu sorcerer-in-training named Aoi Todo.
Introduced as an adversary during an interschool competition, Aoi is a student at the rival Kyoto Jujutsu High School. His debut is prefaced by apprehension by Yuji's upperclassmen -- and, indeed, when Aoi does appear, his first actions involve attacking Yuji's friend, Megumi Fushiguro. One of his earliest encounters with Yuji begins with a fight as well. After this rocky start to their relationship, however, the two become best friends, and then brothers, in the span of one battle. Despite its fast pace, the development of their relationship works because of a few, clever writing techniques.
Although the two don't meet until Episode 14 of Jujutsu Kaisen, the groundwork for their bromance can be found in the second episode. Aoi's perception of other boys, true to their high school age, relies heavily on their "ideal type" of women: In Episode 8, during Aoi's first few scenes in the anime, he grills Megumi about the kind of women he's attracted to and, dissatisfied with the answer, proceeds to beat him up. Avid viewers may recall another scene in which a character considers their ideal woman to be an important component of themselves.
In Episode 2, Yuji introduces himself to his school principal, Masamichi Yaga, by describing his type as "Jennifer Lawrence." The moment is played for comedy and, over the next few episodes, one might believe it to be nothing more than a gag. However, this is a connection that ties together Yuji and Aoi, even before they share a scene. In Episode 15, when Yuji faces off against Aoi during the interschool competition, viewers aren't surprised that Aoi asks him about his ideal type. Yuji's answer was already established in Episode 2 and, when he repeats it, Aoi's reaction makes sense for his character.
Because Aoi relies so heavily on this one factor to determine the possibility of friendship, he rejoices and summons his overactive imagination when he hears Yuji's response. The show cuts to a fantasy in which he attends junior high with Yuji. The imaginary flashback is delicately detailed; it's comedic, but simultaneously makes the viewer feel nostalgic for youth by invoking a classic love confession subplot. After explicitly showing the audience the extent of Aoi's delusion, the series cuts back to the present reality. Aoi, who is older and more experienced, turns his fight with Yuji into a lesson. Then, high-level Curses infiltrate the competition.
The introduction of a shared enemy tightens the bonds between Aoi and Yuji. As they battle Hanami, a special-grade Curse, Aoi encourages Yuji to employ the lessons he'd learned during their earlier fight. He helps Yuji achieve a new skill level and, after Aoi reveals his own special move, the two take control of the battle against evil. Throughout their scenes, Aoi refers to Yuji using terms from his junior-high fantasy, such as, "my best friend." Yuji is confused at first, but as the battle rages, and he is excited by adrenaline, he begins to respond to Aoi with the same affection.
The nicknames offer comic relief during the otherwise-intense fight, and they make sense for the moment, because both characters are riled up. This sequence is where most of their relationship's development occurs and, by the end, they are moving in harmony and calling each other "my brother." When the dust settles on the battle, Aoi continues to treat Yuji with the same adoration.
Yuji, on the other hand, remains consistent with his non-delusional character and admits he'd only been caught up in the moment. By allowing him a chance to reflect on the quickness of their bromance and draw back from the friendship, Jujutsu Kaisen cleverly prevents itself from rushing their relationship. With the promise of more content, Jujutsu Kaisen leaves viewers hungry for more, permanent, development of these soul brothers.