Akitaka High School is a high school located around Yamaboshi High School. It is well known for its delinquent students. Their uniform features a green blazer with a white shirt underneath, a red tie, and grey pants.
Some students from Akitaka High School were hitting on girls from Yamaboshi High School and started to get rough, when Yui Kiriyama was around in episode 6. Due to the "unleashed desires" of the Kizu random arc, she attacked them and reportedly went too far, causing the police to be involved.
Later on, Kaoru Setouchi hires three students from Akitaka to thrash the preparations of the Student Cultural Society for the club exhibition in Episode 16. Later that night, these same students are overheard discussing the operation by Himeko Inaba, who attacks them in a rage, causing them to kidnap her and bring her to an abandoned warehouse near Yamaboshi High School.
In episode 17, while holding Inaba, tied up and gagged on a couch in the warehouse, they call Setouchi to the warehouse and discuss what to do, annoyed with the current situation. The brown haired student suggests doing something due to the particularity of bringing Inaba to an abandoned warehouse, causing the leader to ask him if he wants to be a criminal, with the red haired student claiming that "they are already criminals" and that this job was "no longer worth what Setouchi had given them." When Setouchi arrives, she claims they were going too far, prompting a retort from the red haired student that they were only doing this because she asked them to destroy the Student Cultural Society's presentation. When she retorts that she only hired them because her friends were egging her on, the brown haired student gets irritated and slaps her to the ground, prompting an angry glare from Inaba, which is noticed by the Brown haired student. As he stares her down and asks what she is looking at, Taichi Yaegashi, Kiriyama, Yoshifumi Aoki enter the warehouse at that moment prompting surprise. The leader confronts and tries to threaten them into leaving, but is punched to the ground by Yaegashi and Yoshifumi simultaneously, causing the other two to attack the group, but they are defeated and knocked unconscious by Kiriyama. During that scuffle however, the leader makes his way to the tied up Inaba and pulls out a knife holding it to her neck. As Kiriyami, Yoshifumi and Yaegashi freak out, he yells at them to shut up and that anything that happens to Inaba will on their head, and that Setouchi was to blame for asking them to ruin the presentation. As Yaegashi tries to calm him down, saying they will leave them alone if they release Inaba, he retorts that he doesn't trust them. At that moment, Nagase Iori enters the Warehouse, and says to the leader that "they're in a stalemate" and that he won't be able to make it out alone, but she'll help him because she "has a bone to pick" with the Student Cultural Society, and that "the enemy of my enemy is my friend". Given the shock of the rest of the group, the leader buys her performance, allowing her to get closer. As Nagase starts to get flirty while getting closer and taking a hold of his arms, asking him "what do you need me to do"?, he lowers his guard and moves the knife away from Inaba's neck. At that moment, an emotion transmission from Nagase occurs, prompting Kiriyama to move in. As he notices and tries to shove Nagase off, she grabs his arms that she had had a hold of, and Kiriyama knocks him out with an elbow to the face.
Later on the next morning, as the students from the Student Cultural Society are walking across a bridge, the leader walks up from behind them dragging a pipe, and swings at the group. Yaegashi shields Inaba and is knocked out. Inaba later states in the infirmary that he escapes from this attack.
It is later stated by Maiko Fujishima, that using her father's (a high ranking police officer) help, her and Inaba took "very good care" of the three students who trashed the presentation and kidnapped Inaba, and that "they will never try to harm them again". What exactly was done is not mentioned in the anime, although it can be inferred that it was something frightening.