Arisu is one of the most intellectual students at Advanced Nurturing High School and is highly respected for her status.
School Chairman Sakayanagi Edit
Arisu has a close tight-knit relationship with her father Mr Sakayanagi, who also serves as the chairman of the high school she is in. However, this connection wasn't the reason why she got into the A-Class as it was revealed that under fair circumstances, Arisu has the capability to have mastery over most of the points of assessments — which, indeed, deserves to be among the ranks of the best students of her generation.
Class A Edit
She and Kōhei are often seen together and as representatives of Class A, they get along very well. It appears Arisu is the leader in their standing as Kōhei is shown addressing her when asking for her thoughts on the matters with other classes. Despite their partnership, it is mentioned by Honami Ichinose that the two have disagreements on how to properly run things.
It seems she doesn't mind doing things behind his back or discrediting as she had Masayoshi Hashimoto make a deal with Kakeru Ryūen after discovering Kōhei had made his own agreement. Her actions led to him being criticized for his poor judgment from the class, this shows she has no real concern for his reputation.
Kamuro is part of Sakayanagi faction within Class A. Kamuro is Sakayanagi's right hand(Stated at Volume 6 short story).
In short story in Volume 6 Sakayanagi can be seen teasing Kamuro and also indicates that Kamuro is ordered to monitor Katsuragi but after he withdraw from the contest of leadership for class A Sakayanagi ordered Kamuro to monitor Ayanokoji next.
In Volume 7.5 Kamuro searches for Sakayanagi and found her having a chat with Ayanokoji at the mall, upon meeting with them Sakayanagi asked Kamuro about her thoughts about Ichinose. Sakayanagi told Kamuro that she have the same problem with Ichinose, since Kamuro's evaluation of Ichinose is high she can't believe that Ichinose would have the same problem as her. Later Sakayanagi asked Kamuro why she didn't ask anything why Sakayanagi is discussing strategies with Ayanokoji which she find suspicious.
In Volume 9 She told Ayanokoji how she met Sakayanagi. A week after the entrance ceremony Kamuro left a convenience store when she met with Sakayanagi. Sakayanagi accompanied her upon leaving then Sakayanagi ask Kamuro if she is shoplifting but Kamuro denied it but Sakayanagi continued her inductive reasoning towards Kamuro's action in which she cannot deny anymore and pull out a can of beer that she had stolen. Seeing how the current situation she told Sakayanagi to just report Kamuro's action to the school but Sakayanagi it and told Kamuro that Sakayanagi had grown to like Kamuro and ask her to be her first friend and that Sakayanagi will hide the shoplifting done by Kamuro in return for her do her some favors with that Sakayanagi will turn blind eye to Kamuro's shoplifting then and in future if she does it again. Sakayangi told Kamuro that her instructions will be anything but boring and can replace the thrill Kamuro find in doing shoplifting. Later revealed by Ayanokoji in his reasoning that Kamuro was used by Sakayanagi to lure Ayanokoji to take action to save Ichinose by telling him the same problem that Kamuro and Ichinose did.
Class C Edit
She appears familiar with him as when she and Kōhei were checking out the scores of each class, they saw Class C was catching up and she knew it was due to his efforts calling him persistent. They meet face to face in the courtyard where they spoke with Kakeru remarking on how it looked as if she established her rule in the school very quickly. He swore to her that he will take down all the classes including hers so that he could rule the school as she found his declaration interesting and accepted the challenge.
Class D Edit
No direct interaction has been seen yet between the two in the anime.
In the light novel, at the end of Volume 5, they have encountered each other, as she states she knows everything about Kiyotaka and the White Room, as well as his past. According to her, she knows him very well in fact, though he doesn't seem to recall her.
In her short story, she revealed in her dream about the sports festival how he seemed faster than Manabu in the race between the two. When she woke up from her dream, she requested Masumi to watch Kiyotaka closely, as she wondered on the reason why he chose to come to this school in the first place, and his placement in D-Class no less. She noted how much has grown since the last time she saw him and states how she will continue to look forward to their next encounter, while also expressing her desire of making him hers. She also didn't seem to mind the idea of becoming his enemy in the near future.
It is later revealed in Volume 7 that Arisu had visited the White Room along with her father eight years ago and had witnessed Kiyotaka's succeeding in the training the facility put him through, however how much she knows about him is yet to be revealed.
In Volume 7.5 Sakayanagi met Ayanokoji at Keyaki mall and they had a small chat with regards the fall out within class C and that Sakayanagi had a suspicion that Ayanokoji may be behind it. Ayanokoji stated that he knows that Sakayanagi is the daughter of the school chairman.
In Volume 9 Sakayanagi called Ayanokoji to meet up, upon meeting each other Sakayanagi state that Ayanokoji moved behind the scenes on her attack to Ichinose which made her stand up oh her own. Ayanokoji told Sakayanagi that he unraveled that Sakayanagi used Kamuro to lure him to take action. Later on Sakayanagi challenged Ayanokoji to battle her in the next exam with the conditions of if Ayanokoji win Sakayanagi will drop out, on the other hand if Sakayanagi win she will reveal to the school about Ayanokoji being the mastermind behind class C.
In volume 8, their first encounter was during the special exam of Mixed training camp where Yamauchi was chatting with his friends and didn't notice Sakayanagi calling out to him to look out which tends to them to collide with each other, Yamauchi offered to give Sakayanagi a helping hand but Sakayanagi refused and and told Yamauchi there was no need for his concern then he left saying to his friends that Sakayanagi is cute but clumsy.