Hiyori Shiina

Appearance
Hiyori has mid-back length silver hair that has black ribbons and light purplish eyes.

She is usually seen wearing her school uniform.

Personality
Hiyori is a quiet girl, although she is occasionally seen smiling.

She always carries books with her in her bag in case she meets someone who shares the same interest in literature as her. Since nobody in class 1-C is into literature, she doesn't have anyone to talk to.

She always speaks politely. She dislikes how the classes are competing with each other, wanting everyone to be friends.

She genuinely wanted to befriend Kiyotaka Ayanokōji after he helped her reach for a misplaced book in the library and they started to talk about mystery novels.

Plot
Hiyori made her first debut in Volume 6 when Kakeru Ryūen asked her to accompany him to give her plans for spying Class D. They started with greeting the members of the Ayanokōji Group who were studying together around a group table. After refilling her coffee cup, Haruka Hasebe dropped the cup on the ground after stumbling over her bag. The coffee cup was then crushed underfoot by Kakeru as the group from Class C confronted the Class D students. This caused tensions between the two groups to rise. A few arguments were tossed around and Hiyori was left alone by Kakeru. Hiyori apologized to Haruka for Kakeru's blunder and claimed that she doesn't want to spy Class D though she's otherwise interested.

As they discussed the identity of "X", the mastermind that works underneath the shadows in Class D, she intuitively claimed that it probably wasn't Suzune Horikita. Haruka and Akito strongly believed contrarily since nobody in Class D is superior to her — and that Suzune's the only one that comes to their mind as the possible candidate for X's identity. Hiyori's hunch, though, stems from the scenes where Kiyotaka frequently orbits Suzune whenever their class faces demise and downfall, leading her into an intuitive hypothesis that, perhaps, Suzune's just a cover-up. While Teruhiko snobbishly turned down Hiyori after she "supposedly disturbed" their group's study routine, Haruka instead defended her and expressed her gratitude for replacing the coffee she dropped earlier. Strangely enough, the amount of sugar placed and agitated into Haruka's coffee by Hiyori was similar to the amount Haruka put in, to begin with.

In Volume 7, between the bookshelves under the library's section for the mystery genre, Kiyotaka met Hiyori. While the former was thinking on borrowing another book, he observed a girl who was trying hard to reach the book titled,  by. Kiyotaka helped the girl without realizing that it was Hiyori. After he grabbed the book and gave it to her, the latter expressed her gratitude, and then afterwards, Kiyotaka spontaneously asked whether Hiyori likes Brontë's works or not. She responded by saying that she doesn't have any special preference over the author and she just wants to put the book in the right place, in the right shelf, in the right section of the library.

After her disclosure, with an inquisitive outlook, Hiyori noticed the book titled,  by, that Kiyotaka was holding — the exact book that he had received from Suzune. That book, as Hiyori claimed, was a popular masterpiece that was being borrowed by a lot of sophomores, making the book's availability rare. She wanted to re-read it but didn't have the chance to borrow it. However, Hiyori stated that there's no problem with Kiyotaka borrowing the said book since she had a collection of interesting books in the library at her disposal. She boldly declares that she'll read each of them until she graduates.

Kiyotaka was about to leave the scene to execute the purpose he initially had in the library, but Hiyori didn't seem to be satisfied with their small talk after finding someone who seemingly has similar tastes to her when it comes to books. To continue the conversation further, Hiyori asked if Kiyotaka wanted to borrow another book, to which he denied. Hiyori then immediately turned her attention to one of the shelves in the mystery section and asked if he had already read ' works. Kiyotaka claimed that he has read 's but not any of Dorothy's. Hiyori recommended the first among ' series by Dorothy — '. She affirmed that once he starts reading the said book, he'll be entranced to keep reading the sequel.

Hiyori noticed that Kiyotaka was not particularly interested in the matter but didn't have the heart to refuse her, so she immediately apologized afterwards for talking incessantly about books. He cleared up her uneasiness by telling her that he was just perplexed for a while but was genuinely interested in borrowing the book she recommended. Hiyori was pleased with his response, thus, inviting Kiyotaka to have lunch together. While the latter didn't expect this development — thinking that the whole thing is a fragment of Kakeru's plan — the former stated she's just a girl who doesn't have friends to talk about novels. Though classes 1-C and 1-D are currently in conflict, since she doesn't have any interest in joining either of the parties involved, she stated that mingling with him will not be a problem.

After mutual consent, both of them took lunch in the cafeteria. There, Hiyori had a problem in choosing a meal from the menu but in the end, she bought what Kiyotaka had chosen. Kiyotaka offered a helping hand after noticing that Hiyori was having trouble handling her tray due to her bag. After a few dialogues, the former went to carry the latter's bag and noticed that it was quite heavy — due to the fact that it was filled with mystery-related books. As they sat next to each other, Kiyotaka opened the conversation by asking her whether Hiyori usually had lunch in the cafeteria or not. She denied the question and claimed that she always bought lunch at the convenience store in the morning and ate them in the classroom, so technically, it was a rare event for her. She asked the similar query to him to which he answered that he preferred the taste of food in the cafeteria than in convenience store.

Meanwhile, in Kiyotaka's monologue, he noted that the way Hiyori held the chopsticks was exceptionally charming. After that, Hiyori affirmed that the cafeteria food was delicious and the way Kiyotaka compared the taste of foods sold between the two sources will be kept in mind. The latter then asked whether it was the former's first time to eat at the cafeteria, to which she replied that it was certainly the case. She wanted for so long to have lunch there before but lost the heart to do so given that, to her, it's too far from her classroom. Following the scene where they finished their meals respectively, they talked again about books. While Hiyori was taking out the book from her bag, Kiyotaka immediately acknowledged that her choice of the book was nice. Knowing and confirming that both of them indeed liked the mystery, Hiyori looked elated. Kiyotaka noticed that the book she took out of her bag wasn't from the library. She confirmed that it was from her personal collection of books that she always brought. The lunch break ended with Hiyori allowing Kiyotaka to take the book titled,  and he promised afterwards to return the book to her soon.

In Volume 9, rumors posted on the school forums had circulated around the entire 1st-year, putting the classes of the affected students in disarray and causing conflict to arise. Daichi Ishizaki, a student of Class C was one of the students subject to the rumors. Because of this, Daichi, along with other students of Class C, decided to confront Masayoshi Hashimoto from Class A, who were the ones suspected of spreading the rumors. Hiyori, along with Mio Ibuki and Albert Yamada accompanied Daichi during his meet up with Masayoshi, who also brought Hayato Kitō along with him.

Hiyori was the one to lead the conversation, asking Masayoshi if it was Class A who were behind the rumors. Masayoshi denies this, which causes Daichi to quickly tense up and interject, but was immediately interrupted by Hiyori, requesting him to let her handle the situation. Hiyori continued to press Masayoshi for answers but he showed no signs of giving in. He argued that he just helped spread rumors about Honami Ichinose and states that he had no idea of the source, as he already told Kiyotaka and Akito Miyake, who were also present. Hiyori doesn't buy his argument, calling it an excuse. Hearing this, Masayoshi decided to take a different approach and pin the blame onto Class C, accusing them of being behind the problems. He also quoted one of the rumors posted at the school forums which was about Daichi being a juvie during his elementary school days. At that point, Daichi could no longer stand still and snapped, but was prevented by Hiyori, who grabbed him by the wrist. After further provocation of Masayoshi, Akito decides that Hiyori isn't enough to avoid Daichi causing trouble and stepped in. Because of this, Daichi tells Akito to mind his own business. Meanwhile, Hayato, who had been silently watching the scene unfold, took a fighting stance against Class C, ready to accept their challenge. Realizing this, Akito told them off, emphasizing the rules of the school regarding disputes. Masayoshi then responded that the student council president at that time, Miyabi Nagumo, was willing to turn a blind eye. To prove this, he threw a kick at Daichi, but was quickly intercepted by Akito.

Soon enough, a fight broke down between Daichi and Masayoshi, with Mio and Hayato backing up their classmates. Akito, who was in the middle of the fire, tried his best to calm the situation down but to no avail after being held down by Albert. Before the situation worsened, Hiyori declared her stance to Daichi, who was shouting at Masayoshi. Hiyori reasoned that they won't ne able to bring out the truth from Class A even if Daichi manages to defeat Masayoshi and Hayato. Although Daichi felt bitter of backing down, he was convinced of Hiyori and listened obediently. Right after, Akito was also freed from Albert's hold under Hiyori's orders. Following that, she apologized to the Class D students present after getting them involved in the matter. Seeing this, Masayoshi complained, saying that after being accused and beaten up, they were just gonna leave, to which Hiyori responded with asking for forgiveness. Understanding that there aren't any benefits in dragging the solution any longer, Masayoshi gave his final warning and left the scene. With that, Hiyori successfully defused the conflict during the confrontation with no one left injured.

In Volume 11.5, during their spring break, Hiyori invites Kiyotaka and meets him in front of Keyaki Mall. Eager to talk about books, the two of them go inside a café where they continue their conversation which Kiyotaka noted that he cherished the opportunity. Right after, as Hiyori was about to show Kiyotaka the books she brought along with her, she suddenly remembers something and shifts the conversation regarding that. However, before going into detail, students of Class D, Kanji Ike and Satsuki Shinohara, enter the café and take the seats beside Kiyotaka, who they didn't notice. Hiyori states their names and proudly affirms that after a year had already passed, she got to know more students of the other classes.

Through mutual interest, Hiyori and Kiyotaka kept silent and listened to the conversation of Kanji and Satsuki, which was about the future of their class after losing against Class A in the Event Selection Exam. Satsuki asks Kanji who the person responsible for their loss was, in which the latter replies that it was his fault, leading the former to be surprised. After that, Kanji shifted their conversation towards their relationship, which caught Hiyori and Kiyotaka's attention as they looked at each other. However, before Kanji said anything, Satsuki interrupted after finally noticing Hiyori and Kiyotaka right next to them. Realizing this, Kanji became flustered, saying that Kiyotaka should've greeted him instead of sneaking around. After that, Satsuki asks Kiyotaka if he was on a date with Hiyori, in which he replies that that isn't the case and returns the question about Kanji and the former. The former quickly denies this, which led Kanji to insult her. This caused them to argue and leave Hiyori and Kiyotaka alone.

After that, Kiyotaka asks Hiyori regarding what she was saying earlier. She states that it was similar to what had happened between Kanji and Satsuki, which brought ideas of confession and alike to Kiyotaka but they were immediately rejected. Hiyori brought the topic regarding the special exam to the table. She then asks if Kiyotaka was the one who changed Kakeru Ryūen, which he noted that Hiyori asked with her eyes filled with conviction. Because of this, he doesn't deny her, and instead, asks for her reasoning. Hiyori says that it was her simply putting the pieces together. She apologizes for bringing it up and affirms her nervousness because of what she had to reveal to Kiyotaka. Hiyori states that she would definitely regret revealing what she knew to Kiyotaka if they end up no longer talking to each other after, in which Kiyotaka notes that she should've kept it to herself. Hiyori says the reason behind her action was that so they could develop further. Kiyotaka inquires further but Hiyori replies that she didn't know what she was saying herself.

After that, the two of them talked about how Kakeru confronted Class B in the special exam, with Hiyori stating that his methods were dangerous that even though the class they were against have kindhearted students, they wouldn't tolerate his strategies. Kiyotaka questions why Hiyori didn't try to stop Kakeru before he executed his plans, to which the latter replies that he wouldn't listen to her even if she did. Kiyotaka agrees and asks Hiyori if there is any way Kakeru could be stopped, in which Hiyori replies that someone even more powerful than him have to criticize his way of thinking. After that, Kiyotaka asks Hiyori if she could help him pass a message to Kakeru, to which the latter agrees. Kiyotaka then says that if it were him, he could've secured more than five wins using a better method. Hearing this, Hiyori seemed grateful and says that she will pass the message on to Kakeru.

Hiyori and Kiyotaka parted ways shortly after the former gave books to the latter for him to borrow. Kiyotaka noted that he should change his evaluation of Hiyori, regarding her as a friend with mutual interests rather than a student from the same year.

Academic Abilities
Not much is known about Hiyori's academic background, but one thing is certain: the scores she got on her assessment by the S-system indicates that she belongs to the upper echelon among her colleagues.

Intellectual Abilities
Hiyori is known to have a sharp intuition which is why she is sometimes tasked with info gathering and surveillance, though she is never serious about it.

When Haruka Hasebe dropped her empty coffee cup on the ground, Hiyori managed to know exactly how much sugar was in it, to begin with, and get a new cup of coffee with the same sugar amount for Haruka later.

Hiyori was able to figure out that the person Kakeru Ryūen was looking for in Class D was Kiyotaka Ayanokōji after suspecting that he stepped down from his position after being defeated, and that Daichi Ishizaki taking him down was merely a cover-up.

Name Etymology

 * Hiyori's surname Shiina consists of kanjis that mean "oak, mallet" (椎) (shii) and "name" (名) (na).

Trivia

 * The reason for Hiyori's evaluation of Class C is due to lack of teamwork skills.
 * Hiyori ranks #30 in "Female Character" category in the 2021 edition of 's  guidebook.
 * For the 2nd Year arc, when asked about her aspirations for the next year, she answered  'To read as many books as I can in the library. And searching for a new book to meet.'