Hiyori Shiina is one of the students of Class 1-C who is a loner. She's a quiet girl, though sometimes she is seen occasionally 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.

Spoiler

She encounters Kiyotaka in the library, and they find themselves having the same taste in books. As she always wanted a friend who has similar interests as her, their friendship gradually blossoms and she refers to him as her "reading buddy". She slowly starts developing romantic feelings for Kiyotaka.