Airi and Kiyotaka are classmates, but they don't take notice of each other until Ken Sudō's case. They first met when he and Kikyō Kushida went to ask her for help, but she tried to run and broke her camera. Later, he accompanied her to get it fixed and helped her by telling the clerk to send him the notice for the camera instead of her because of the flirty store clerk, as she looked at him blushing and thanked him for his actions.
She later asked him about his thoughts on the Sudō's case, when he told her that it's up to her and that the decision she makes shouldn't burden herself. She blushes at his words and gazes at him for a while but became flustered when Kikyō returned. Because of his words, she decided to help save Ken and goes to the hearing.
When Manabu Horikita hinted that one side could be lying in the case, Airi got intimidated but Kiyotaka quickly intervened by saying he believed her, much to her relief. After the hearing, she apologized for not working up the courage to help out sooner, but he told her not to worry. She was worried about Kiyotaka when Manabu tried to attack him. 
A day later, she looked intently at Kiyotaka's desk, before he appeared surprising her. He told her to be at ease and stated that if she ever needed him, he'll be there for her. Airi was touched as she blushed and smiled before she tried to ask him something, but he had to leave though he did promised to hear it later.
When she was being followed by the store clerk, she quickly phoned Kiyotaka, he got confused by her strange tone and tried calling her back. As she was about to be assaulted by a store clerk (who previously made advances on her), Airi reflected on Kiyotaka's promise to help her anytime and tried to reach for her phone, but to no avail. However, Kiyotaka came to her aid by arriving on the scene and catching the man in the act before threatening him with incriminating evidence. When the man tried to flee, he was skillfully ambushed by Honami who Kiyotaka had accompany him along with the police. After the man was taken away, Kiyotaka expressed relief that they had exchanged contact information which allowed him to find her. She apologized for dragging him into the mess, but he comforted her by saying the incident was not her fault and he told her to enjoy her status of being an idol. Airi then decided to stop hiding her secret and apologizes to him and took off her glasses to embrace her status.
Kiyotaka offered to give advice in the future for any burden that she may face, before helping her up as she looked at him in surprise and took his hand. On her feet Airi faced him, she blushed and remarked on the look he gave her stating that she has never seen him make such face, as he was confused by her words though she shrugged it off with a smile. It is most likely at this point that Airi developed romantic feelings for Kiyotaka. It appears that Kiyotaka is unaware of her romantic affections for him.
During summer break, she accepted his invitation to come to the pool. When most of the students started splashing each other, she did the same to Kiyotaka but was seen nervous and slightly blushing when he looked at her, causing her to apologize and sink in the pool in embarrassment. 
On the school cruise, when she tried practicing to confess her feelings to Kiyotaka, she was seen blushing as she struggled with her words as a result. She was surprised when Kiyotaka appeared before her. After learning he didn't hear, she was relieved and instead asks Kiyotaka if he could help her in socializing with their class since she still had problems properly talking with them. He agreed as she became elated at this, grabbing his hand out of gratitude.
During the survival test, she was paired up with Kiyotaka and traveled through the forest with him. When they discovered a spot, Kiyotaka hid her and covered her mouth after she tried to move ahead when Kōhei Katsuragi appeared. While being held tightly by him, Airi was shown blushing full red before the coast was clear, as Kiyotaka released her. He apologized for his actions, but she was seen still heavily blushing and squirming on the ground to his confusion. Later when Suzune refused he asked her to come along with him, to look for branches for starting a campfire. She was happy when he invited her.
Airi was also shown talking to Kiyotaka as he asked her if she wanted to stay in a pair with him, to which she confirmed and apologized for dragging him down in the search, he soon asked her if she was afraid if people started talking to her about them, as she told him that she didn't really care about that, explaining that she was down on the school trip at first due to not having friends, but now was glad that she came. She then looked him in an admiring way, stating regrettably that she wanted to have her camera so that she could take a great picture of him, which would hint that she probably thought that he would look good in a picture.
At the final day of the survival test, she was helping Kiyotaka cleaning up the campsite, where she asked him how many points that he thought their class were going to get by the end of it. Kiyotaka then wondered about that and looked at Yōsuke Hirata afterwards. Due to his real thoughts, it is unknown what he really thinks of her.
In the light novels, he doesn't manipulate her unlike everyone else around him. It seems he genuinely cares for her, as it is shown that Airi is the only person that Kiyotaka down-right simply refuses to take advantage of, manipulate or use as a tool on his various grand schemes for the sake of their class, proving that he truly cares for her. Furthermore, in the light novel, she forms a close bond with Kiyotaka, where she is shown to be always by his side. At the same time, Kiyotaka and her mutually refer to each other on a first-name basis, showing how incredibly close they are to each other. Airi was also cheered on by Kiyotaka during the sports festival and was also treated by him after the festival, causing her to become happy and grateful.
During the panty thief incident, as everyone started accusing and mistrusting Kiyotaka for being the culprit with the other boys, Airi was the only one who defended him and even helped him look for firewoods when others refused. Kiyotaka also didn't approve of Haruki's questionable advancements towards her and protected her by not complying with his order of leaving the two of them together, by explaining her timid nature and fear of others.
When she was delivered a love letter by him, she mistook it for Kiyotaka's letter and got flustered about it not knowing how to process the overload of information. However, she was corrected by him when he said that it was from someone else who forced him to deliver it.
Her romantic feelings for him were further shown in the light novels as well, as she got very jealous when Maya Satō happily clung to his arm and remarked on how cool he was in a flirty tone. Later on at the cinema, she overcomes her shyness to clear up her doubts by directly asking him why Maya is acting so intimately with him. Kiyotaka replied that she's just his partner at the recently finished exam "Paper Shuffle". Airi immediately retorted to Kiyotaka that he could have let go of her hand if he really wanted to, while he reassured her that he won't be repeating such same mistake again.
Despite not knowing what his real thoughts are, he is shown to dislike making her upset or unhappy for some reason. It was also hinted in Volume 6 that the reason he pushed her to join his study group was that he knew her romantic feelings for him and wanted to cultivate her as a person by introducing her to his friends.
In her short story though, Airi revealed that seeing Kiyotaka and Hiyori having lunch together, talking about novels and stuff in the cafeteria makes her heartbeat go wild — chased by a fervent fear that something romantic might bore out of the two. She expressed great relief after confirming with Kiyotaka that there was nothing between them. With pure rhetoric, Airi said that her heart might stop if they were actually on a real date.
Haruka immediately provoked her fears by telling her the possibility that the two might get closer soon. Realizing things would eventually fade if no actions were made, following Haruka's recommendation, Airi resolved to make herself more attractive and appealing to him.
In Volume 7, Airi asked Kiyotaka about his plans for Christmas and who he will spend his time with. Soon after, she met him in his room and gifted him a pair of blue gloves for Christmas.
Whenever girls made moves on Kiyotaka, she is always in the background worrying if he would be taken before she had the chance to approach him. Kiyotaka doesn’t see her in a romantic manner but wants her to be better as a person. She showed her resolve to him by announcing that she will work harder so that she won’t be a burden to their class. He was happy at her progression and hoped it would continue but deep down whenever he sees her, he always had the vestigial feeling of worrying about what would happen to her when he reveals his secret relationship with Kei to her.
Unbeknownst to her and her friends, the people she surrounds herself with were all carefully picked by Kiyotaka so that when the event of his revelation happens, they would be there to guide her through her depression phase and acts as steadfast pillars of support.
In the light novels, Haruka is apart of students who fade into the background like Kiyotaka and called themselves the Ayanokōji Group. Because of her romantic feelings for Kiyotaka, Airi asked Haruka if she can join to which the latter accepted, making Airi a member. It is unknown what their relationship is like but seems to get along as both appear to keep their distance from strangers due to their attractiveness. They both share the same trait of nervousness of interacting with others and in Volume 7 they both were seen hanging out with the other members of their group as well as watching the Class 1-C students, while discussing Christmas and among other things.
They don't have much of a relationship, as Airi appears not to trust Kikyō. They did not have much interaction until Episode 4 when Airi was pointed out by Suzune as the only person who did not volunteer to help Kikyō prove Sudō's innocence. Kikyō and Kiyotaka soon go to meet with her, but Airi refuses to get involved and runs off. While so, she ends up accidentally damaging her camera. In Episode 5, she invites Kikyō and Kiyotaka to help her repair it and apologizes for the trouble she's caused them though Kikyō did acknowledge her partial responsibility. They appeared to get along well, but Airi did not open up completely to Kikyō. When Kikyō leaves for a moment, Airi spoke more openly with Kiyotaka. Her reason was that his eyes weren't "scary" indicating her mistrust in Kikyō.
They meet again for summer break while hanging out at the pool Kikyō remarked it was the first time Airi hung out with them asking if she liked pools, but she replies that she came because Kiyotaka invited her.
On the school cruise, while talking to Kiyotaka, Kikyō appears which causes Airi to run off. This meant that she is still wary of her, but the extent is unknown.
In the light novel, she doesn't have a good relationship with her as well, due to her wariness of her fake personality. As such, she doesn't associate with her and would avoid unnecessary contact with her.
Haruki is one of her classmates while much interaction has not been shown, they appear to get along. Unknown to Airi, Haruki harboured feelings for her due to both her attractive body and personality which he finds appealing. He even got excited at saying her first name repeatedly and would try to show he was a nice guy by helping out Mio Ibuki. However, Airi doesn't feel the same way about him due to her romantic feelings for Kiyotaka.
In the light novel, during the island test, he asked Kiyotaka to leave both him and Airi together, so that he could get close to her and tell her how feels about her. Kiyotaka, however, disapproved and refused his order, probably due to Airi's own shyness and timid nature of being afraid of uncomfortable situations, much to Haruki's dismay.
He was seen confessed his feelings to Airi during the end of summer vacation, by writing a love letter and made Kiyotaka give it to her for him. She mistakenly thought it was from Kiyotaka, as she got flustered about it not knowing what to do, in which he corrected her afterwards saying that it was from someone else. He then convinces her to read it alone as his responsibility was only conveying Haruki's feelings crammed into the letter to her.
The day after, Airi and Kiyotaka meet up to talk about Haruki's confession. She didn't know how to respond to the letter, so Kiyotaka tells her to just say what she feels. She then tells Kiyotaka that she was going to decline Haruki's confession as she didn't feel the same way about him. When Kiyotaka was about to leave, she stops him and asks if he could stay with her as she doesn't want to be alone. Haruki comes later and he tells her about his feelings. His awkward confession on the reason why he likes her ends with her nervously turning him down. He thanks her for being honest with him, while Airi says sorry and leaves.
Kiyotaka wonders why Haruki isn't being depressed about it and Haruki reveals that she wasn't really his type. Haruki then realizes that he wasn't that serious about her and apologized for making her worry. He understood Airi didn't want to hurt him. He later says that he is going to get over from his feelings for Airi while looking on forward and hopes to find someone else, as Kiyotaka praises him for his maturity.
There hasn't been much interaction shown between them. They first met in Episode 6 where Honami and Kiyotaka came to Airi's aid when she was attacked by a crazed stalker. Honami was the one who gathered security and eventually apprehended the suspect, saving her from the dreadful situation. During summer break, they hung out at the pool. Honami would tease though in a playful manner of a nervous Airi for her close relationship, and her obvious romantic feelings for Kiyotaka, much to Airi's embarrassment. She then adamantly rejects such a notion and tried to cover it up with an excuse. Their limited interactions thus far shows they are on good terms despite being in different classes.