Hiyori Shiina/Relationships

Masayoshi Hashimoto
Hiyori was the one who reach out to he and Hayato Kitō to a meeting with she and her fellow classmates, inviting the two to meet up and have a talk. It didn't exactly worked out as planned for Hiyori when dialogue broke down between both sides after her classmate Daichi got provoked. She acts questionable towards Masayoshi about his involvement in spreading the rumors about not only her classmates but her friend Honami as well. Hiyori did once considered trying to trust Masayoshi's words, but Daichi advised her not to while reminding the former that the Class 1-A was a pathological liar. She is apologetic to Masayoshi when the latter accuses her of freely allowing violence by her classmates to be done to them which Hiyori apologizes for. She doesn't want to see Masayoshi or her classmates getting into a fight, doing what she can by making her point clear that fighting won't get them anywhere in progressing with their talk. Hiyori made a verbal promise to Masayoshi that she will make it up to him and could do nothing but asked for his forgiveness to overlook the trouble her classmates had caused to he and Hayato. However, Hiyori understood that it will be difficult for her to make amends with Masayoshi and people of Class 1-A after that meeting gone terribly wrong on both sides.

Honami Ichinose
During the Mixed Training Camp special exam, Hiyori is able to get along well nicely with Honami, believing it is an honor that she could befriend her. After eating the same food and sleeping together in the same room as one another, she develop and feel a stronger bond with Honami than she would with other students. Once the two became friends, Hiyori develop concern for her well-being as shown when she reach out to Kiyotaka to ask for his assistance in resolving a matter concerning Honami. She dislikes seeing Honami suffering and being tortured mentally by the terrible rumors being spread negatively of her. Hiyori describes Honami as the type of person who was kind enough to be friendly to the former who barely had any friends to talk to except for the latter and a few others. She was willing to assist Honami with her troubles even if the latter did not ask for it. Although she and Honami are mutual enemies from their respective classes, Hiyori still believes that there must be something she can do to help her friend out without intefering in the class conflict. She doesn't mind postponing the discussion with Kiyotaka at a later date and time for her sake, not wishing to cause any more trouble for Honami if it ends up spreading more of the bad rumors about her friend further.

Other B-Class students
When they were first-years, Hiyori express how quite envious she was about the unity and cohesion of Class 1-B students, seeing how harmonious they are to each other compared to her own classmates. She doesn't see any one of them as particular threats to her class other than being a closely-knit group who just work together in unison.

Kakeru Ryūen
Despite Kakeru's intimidating presence, Hiyori remains calm and collected around him. Likewise Kakeru's mannerisms towards Hiyori is different in comparison to his attitude towards their other classmates and even those who work directly under him. He also seems to trust her immensely. Hiyori is cooperative with Kakeru and occasionally offers him her own input of people who leaves a memorable impression on her, accompanying the latter around to meet new people that she has never met before out of interest. Nonetheless, Hiyori doesn't always agree with Kakeru's strategies and actions, expressing her own decision to back out in getting involved with him when it involves directly confronting "X" face-to-face. She doesn't quite understand what was so amusing and fun about hunting down "X," doubting and questioning why he would go so far to meet the mastermind of Class 1-D with so many people accompanying him. Although she felt there was no need for him to go to great lengths, Hiyori is unable to do anything to convince him to reconsider and give up on the matter, allowing him to ignore her question anyway since she is not in the position to decide it for him. She and Kakeru respect each other's personal boundary and space, choosing to care less about his decision as he is her class leader anyway. Hiyori even doubts she herself would be of any great use to him in his grand scheme of things since she dislikes class conflicts to begin with and has no intention in getting involved. She voice her concerns to Kakeru about what he was planning to do when noticing the strange restless atmosphere going on with all her classmates, believing he is the main cause of the unrest. She is perceptive of Kakeru's true intentions in his strategies, quickly understanding what he was planning after being given an quick explanation by him without needing to ask additional questions unless her classmates need someone like her to explain it for them on his behalf.

More so, she doubts Kakeru will listen to everything she has to say, not taking her own suggestions to heart before he follow through with his strategy. She wishes that Kakeru was a bit more dependent on her when reconsidering the framework of his strategy, feeling concern that his methods might end up hurting someone's body physically even if it was not the work of violence such as getting a person sick. She feels the only way to get her message across to Kakeru was through first asking Kiyotaka's opinion who he acknowledge and approve of for advises before reaching out to him. The reason she was able to obtain the position as co-class leaders with Kaneda is solely thanks to the work of Kakeru who selected her for the job after he steps down temporarily.

According to Hiyori, Kakeru couldn't stand to see her always alone and quiet so he reached out and talked to her himself. However, since there were always a lot of people surrounding him, that made Hiyori feel very nervous so she wasn't able to stay together with him or hang out. She makes sure to maintain her distance from Kakeru sometimes whenever he is with them. There were times when Hiyori will accept or turn down Kakeru's invitations to accompany him on his walk unless she volunteer to do it herself. Even if she was down with the idea of accompanying Kakeru, Hiyori doesn't continue hanging around him all the way for too long when there are instances that she chose to stay behind with the people they come across such as the Ayanokōji Group and talk to them once he left her alone. Hiyori thought the group of Class 1-D students were victims of Kakeru's mishaps such as squashing Haruka Hasebe's cup of coffee which she feels guilty of seeing and doing nothing until he left her behind to clean up his mess, offering to apologize in the latter's stead. Kakeru refers to Hiyori under a first name basis though the reason for that is currently unknown. While Hiyori had some misgivings about Kakeru, she still recognizes his true capabilities to lead the class and doesn't believe it was the right idea to expel him when her classmates needs him the most if they're aiming for the top and overcome exams. She suggests he come visit her at the library if he ever ends up finding himself in trouble when his strategy fails.

Although Hiyori's pacifistic nature juxtapose that of Kakeru's belligerent personality, she feels strongly that without him being the leader, their class ranking would inevitably dropped, making him an indispensable person to their class. She also understands that without him establishing a firm grip of the other students, their class would inescapably fall in disarray to establish control, thus, she is willing to help him maintain his authority while turning a blind eye to the things he does that are too unsightly for her.

Daichi Ishizaki
Hiyori and Daichi seems to have a respectful relationship when working side by side together led by Kakeru. She doesn't exactly hold a lot of trust for Daichi's judgement when he is about to get violent with members of Class 1-A, seeking confirmation from him whether he will be on his best behavior during a talk. Daichi is one of the people she has trouble restraining physically once he loses control of himself. For this exact reason, Hiyori would go out of her way to try as hard as she can to reign him in through giving a brief explanation of her own to convince the latter, reasoning with Ishizaki that they need to reflect on their action of using violence and how it doesn't always produce solid results for them like getting an answer out of Masayoshi of Class 1-A. She wants Daichi to be a little more reliant on her in speaking on their class's behalf, desiring to be the one doing the talking for them whenever he is not in the right mind to speak but throw violent tantrums. She encouragingly tells Daichi to bear with the bad situation despite how unfair it was to the latter, having him hear her out that acting violently won't do nothing to clear up or resolve the rumor surrounding him.

Hiyori was open and willing to hear out Daichi's plan when the latter reach out to her and Albert to accompany him. Especially if his plan involves Kiyotaka, she was more than ready to assist Daichi's strategy and be supportive of it without questioning the flaws until later in the meeting. She knows Daichi is the type who doesn't pay careful attention to the exam rules sometime and refuses to point it out for him, feeling it will be meaningless of her to correct everything he suggest to Kiyotaka. For this reason, she lets Daichi carry on with his absurd explanation, reasoning that her intervention won't do anything much to convince him otherwise unless they meet Kiyotaka who can explained it to him in-person. When Kiyotaka is present with her, Hiyori was able to take the initiative and questioningly reveal the flaws of Daichi's strategy without keeping silent about it any longer from her classmate. Once Kiyotaka reaches a decision, Hiyori felt it was her duty to do what she can to stop Daichi from trying to convince him by giving her own reasonable explanation behind his choice. She shared the same sentiment as Daichi in wanting to group up with Kiyotaka and have him join their class.

Albert Yamada
Hiyori seems to have trust in Albert enough that the latter was willing to follow through with her order as a leader of the class. It was implied that she and Albert are on friendly terms with one another as the two are able to cooperate together with Daichi's plan of recruiting Kiyotaka into their group for the Uninhabited Island Exam. Hiyori and Albert seem to know what they need to do next and act in sync when restraining Kiyotaka from leaving the two of them behind when he was acting uncooperative. She lets Albert take Kiyotaka's left arm while Hiyori handles his right arm, knowing how to successfully prevent Kiyotaka's escape. Kiyotaka questions Albert's action of carrying him around suspiciously in the eyes of people but Hiyori gave a silly answer reassuring him that this was her classmate's way of doing it to fool their public surrounding. When she states her opinion and her own points across, Hiyori turns her attention to Albert in seeking for his approval which he agrees with what she got to say without problem.

Mio Ibuki
Hiyori is able to work well with Mio as the two are open to dialogue, having each other's contact information exchanged. This was indicated when Mio texted Hiyori a message about Kiyotaka's plan through her. On the other hand, she shared Kiyotaka's contact number with Mio to help her fellow classmate out of getting in touch with him if they wish to call or message one another. Hiyori prefers to talk things out with Mio when the latter expresses her displeasure of meeting face-to-face in a group, egging her to be patient and remain together. In the karaoke room, she would encouragingly convince the latter to relax and do some entertaining things as a mean of distraction while waiting on Kakeru to arrive at their hangout.

Satoru Kaneda
Hiyori seems to have a cooperative and cordial relationship with Satoru as fellow co-class leaders of the same class together. She seems to have a good understanding about what kind of decision he would have made and follow Kakeru's orders regardless compared to her other classmate Daichi. Hiyori sharply understood Satoru was the type of guy who wouldn't dare to ignore orders from Kakeru or took part in a bad strategy he's uncertain of will be successful.

Other Classmates
Hiyori is the kind of person who feels isolated from the rest of her fellow classmates in the classroom. It was because of Hiyori's personality and how she loves reading books during her spare time was why not so many can find a good reason to reach out to her or form friendly ties with her. Thus, at the time, she had almost no one from the class who are interested in her hobby of reading, as nobody were interested in talking to Hiyori about her liking for literature works. However, after meeting Kiyotaka who she can become friends with, she starts going out of her way to take the initiative herself and establish friendly relations with her classmates. This was apparently the case when she was given the position of leadership over the boys and girls in her class by Kakeru that Hiyori starts to be surrounded by all her classmates who she would not normally be around like Daichi, Albert and Mio. Similar to Honami, she would readily go out of her way to stop her classmates from picking a fight and resorting to violence with other students from a different class, reasoning to them that nothing good would come out of doing this.

Kiyotaka Ayanokōji
Hiyori first met Kiyotaka after Kakeru made a contact with the members of Ayanokōji Group, who were studying around a group table. It is apparent that Hiyori noticed Kiyotaka for an indefinite span of time since she's aware of him as someone who frequently orbits Suzune and knows he is someone who sits next to her in the classroom. However, she initially had a weak impression of him as someone that was not worth remembering until their next encounter at the school's library in the following volume. As the two are from different classes respectively even though they are considered friends, she felt that a day would come when they would have to fight against each other in the future without letting their feelings about one another get in the way of their class competition. She believes that he would most likely be the most dangerous enemy her class will ever face off.

Between the bookshelves under the library's section for the mystery genre, Kiyotaka meet Hiyori by chance and befriended her. When she sees him with a book that she knows, Hiyori immediately opened her heart to Kiyotaka without hesitating. She would go on for several minutes of passionately talking to him about books and all he would do was listen in silence. Hiyori felt apologetic towards Kiyotaka for taking up so much of his time after realizing that she has been speaking with him nonstop until their conversation had almost reached its end but he admitted that he was enjoying himself listening to him. Thus, she didn't want to conclude her discussion with him yet and insisted that they move their talk to the cafeteria, a place she rarely visits until she accompanies Kiyotaka to that location. Hiyori was then recommended by Kiyotaka of how good the food at the cafeteria were as it was freshly made, leaving her to agree with him and accepts his words as true after she taste them for herself. From that point on, they eat lunch there and became best friends who start growing close to each other ever since that meeting in the library and their time spent in the cafeteria. She even presented her schoolbag that was full of mystery novels to let Kiyotaka borrow one out of her own personal collections to take home and read.

In the end, she thought to herself that carrying the schoolbag had proven to be worthwhile and a meaningful experience to Hiyori as it has help her find someone like him who understood well what her reading interests and hobbies are. She was delighted and relief to know that the two of them are similar since they both enjoyed reading mystery books and discussing about it. Whenever they are in the library or some other place together, Hiyori would go out of her way to recommend Kiyotaka some books that she likes to read, understanding he shared the same preference and was very open to sharing new information about new novels adding to the bookshelf. She was even willing to let Kiyotaka hold onto her things such as her schoolbag when carrying it proves difficult when taking her lunch tray. When she was unable to decide on what to eat, Hiyori just ended up choosing the exact choices of food as him to have a taste in the end and complimented his taste of food. More so, she expresses genuine interest in what sort of topic Kiyotaka will bring up to the forefront such as the subject regarding China.

According to Mei-Yu Wang, Kiyotaka and Hiyori are able to talk naturally to one another. She regards him as her reading buddy in the library and always report to him about the latest information regarding some new books being added to the school's library. She thinks that if it was Kiyotaka himself, he may be the one person who can possibly clear up the matter with the rumors surrounding her friend Honami Ichinose than anyone else could that not even she would accept neither Suzune Horikita or Yōsuke Hirata for the task. Kiyotaka was the one person from Class 1-D she was willing to reach out and ask for his cooperation in helping a friend. Hiyori was quite careful in not asking help from Kiyotaka sooner as she didn't want to put him on the spot when they were still with her friend Mei-Yu Wang, knowing the right time and place for that sort of talk later. Hiyori has even shown a good amount of patience in waiting for him to sort out his matter when he was busy checking his mailbox, not looking to head back to her room until she has her talk with Kiyotaka first. Hiyori welcomes his silent presence, able to keenly understand the natural love for the library each one of them had to the point they don't see a need to hold an excessive conversation. The act of reading a book was, in itself, a form of conversation she is having with Kiyotaka without needing to openly say a word back to him. She was able to establish a first-name basis with him to show how far their friendship had grown in terms of their overall closeness much to the surprise of others.

As he is a very precious and irreplaceable friend to her, she can't help but show some signs of concern for Kiyotaka whenever there was a possibility that neither of the two will ever see each other again if one of them ended up getting expelled from school. Even though they were supposed to be enemies from opposing classes, she would still go so far as to convey her worry and begged Kiyotaka to do everything in his power to avoid expulsion. At some point in time, she and him had shared their contact information with each other, having his phone number. Hiyori thinks he is the one person among the very few she knows from his class who can help her with a problem that troubles her personally as it has nothing to do with class conflict but about her concern for a friend. She will reach out to him for cooperation on what the plan is to save people she cares about like Honami. She describes Kiyotaka as very intelligent and precocious for someone of their age, picturing him and his levelheaded personality to be always relaxed and easygoing around her. For this reason, the way that he often carries himself was what allowed Hiyori to grow and become increasingly fond of being with Kiyotaka over the course of time they spent hanging out together. She even intuitively made special seat reservations for Kiyotaka and his classmate in the library ahead of time without the latter asking for it. Hiyori believes such way of thinking she had towards Kiyotaka was not because of how the former views him as someone of the opposite sex, telling herself in her mind that this was what she feels about the latter as a person. As she hardly has anyone to talk to, Hiyori invites him on a date thinking it was necessary for her to gain some experience of going out to play with a close friend whether it was a day-off or not. Although she tries not to think of Kiyotaka as someone of the opposite sex, Hiyori ends up doing it in the end when she is with him. She dislikes the mere idea of keeping Kiyotaka waiting for her after he arrives before the former and vows to come early then show up late to their date.

Just thinking about herself troubling Kiyotaka and disappointing him is what she wouldn't like to see happen in their meeting. When she starts feeling something fluffy deep within her own heart, Hiyori believes the best way to investigate it further and sort out her thoughts was to meet and talk with Kiyotaka himself to better understand and see for herself. She has the conviction and consideration to speak the truth of her thoughts about him and her class, knowing full well it may jeopardise her own friendship with Kiyotaka but felt their relationship won't show further signs of development between them if they don't go past this hurdle. She desires to strengthen her relationship with Kiyotaka beyond just friendship alone. She regards him as someone worthwhile taking her time off to go visit and ask for his opinion when Kakeru wouldn't always hear her out or listen to her suggestions unless the message came from Kiyotaka himself who she noticed that he is acknowledged and approved of by her classmate. Later on, Hiyori starts developing romantic feelings towards Kiyotaka as shown in her monologue which she says that she wants to spend more time with him even if it's only a second longer. When there was a special exam that requires her partnering up with someone in a group, the one and only person that came to her mind was Kiyotaka and was willing to cooperate with Daichi if he is related to her classmate's plan. She would love to see Kiyotaka transfer over to her class, desiring to go along with Daichi's plan if it was to get the latter to change sides and become part of the same classroom as the former. She even remarks how it would be interesting if the two of them who are not from the same class started dating each other boyfriend and girlfriend as Daichi wanted.

Mei-Yu Wang
During the Mixed Training Camp, Hiyori ended up in the same group as Mei-Yu and voluntarily chose to be the one to call out to the latter when she was surrounded by unfamiliar people. Hiyori understood what Mei-Yu was feeling and kindly did her best to befriend her, comforting the latter that she and her fellow classmates were willing to become her friends. When her group was running, Mii-chan had fallen behind out of exhaustion, Hiyori seeing this from behind decides to quicken the former's pace and linked up with her. Hiyori met with Mei-Yu again at the cafe in Keyaki Mall, where the two refer to each other by their first name respectively as a sign of their growing closeness in terms of friendship.

Haruka Hasebe
Hiyori and Haruka met each other for the first time under bad circumstances when Kakeru destroys her cup of coffee, leaving the latter to view her in a negative light. She understood Hiyori was angrily in a bad mood with the former as the latter believes her classmates have went and disrupted the Ayanokōji Group's study session unexpectedly. Hiyori felt guilty for her class leader's aggressive action, choosing to apologize to Haruka on her class's behalf when they refuses to take account of their own actions. She even spend some of her own private points on buying Haruka a new cup of coffee, and putting in the same amount of sugar as the latter did to cheer her up. Although she was not kindly welcome by Haruka but was seen as wary initially, Hiyori is able to somehow make amends in their relationship due to the former's gift of apology being well-received. This in turn, allowed Haruka to finally forgive her and accept friendly dialogue with Hiyori moving forward. She was happily satisfied to see that Haruka enjoyed the taste of the drink made for her. Nonetheless, she knows Haruka talking with her would only served to sap away the latter's energy in no time at all.

Teruhiko Yukimura
She is cognizant that Teruhiko and his friend Akito is not "X" as her class leader Kakeru was suspecting one of them to be. She is able to keenly pick up on Teruhiko's attitude that the latter see her as a spy. Hiyori understood she can't stay around the Ayanokōji Group any longer than necessary since she was seen as an inconvenience by him due to interrupting their study sessions. Like with Haruka, Hiyori is also apologetic towards Teruhiko for causing his group trouble, understanding how bad it was that she and her fellow classmates have gotten in his way of studying and taken away some of the latter's time by talking to her. Realizing that she was distracting him and disturbing his group for too long, Hiyori decides to part ways with him while his attitude towards her still remain hostile and wary as always compared to his friend Haruka.

Other D-Class students
Hiyori grew interested in the students of Class 1-D after Kakeru starts suspecting "X" to be someone from this class. She starts paying a kind visit to each group of Class 1-D students while searching for clues on who the "X" individual may be. Hiyori always often hears about "X" and the potential students of Class 1-D who might be that mastermind all the time in her classroom to the point where she wanted to accompany her classmates during their search herself. Although she can't do nothing but be the one to avoid getting involved in the situation, Hiyori still voices her displeasure at hearing that Kakeru will try to hunt one of those students down, worrying someone might get hurt in the process because of her leader's violent action. Besides Kiyotaka, the other person who she can recall in the back of her mind was Rokusuke Kōenji, believing him to be unique among the lineup of students in Class 1-D.