Matsushita is one of the students of class 2-D. She has a quiet older sister type of personality. She is generally kind to all the boys and girls alike, but she does not actively go out to make friends.
Chiaki had believed from early on in the first year that Class D had no hopes of ever reaching Class A and thus resigned herself to a carefree school life, never putting in any real effort into her academics. She considers herself to be a major underachiever, believing that she could easily score in the top 10% of her class if she truly tried to, but believed it to be pointless as long as she was in Class D. Later on in the light novels, she starts seeing improvements in the class and becomes willing to start contributing to the class. She is also known to be skilled at mental arithmetic and can calculate quickly. She even held her own against Kouhei Katsuragi from Class A in the Mental Arithmetic event in the Event Selection Exam.
Later, in her monologue, she states that she had started to pay close attention to Kiyotaka after the end of year special exam, but she was not romantically interested in him. According to her, she was probably among the top 10% of students in their year, but had not revealed her abilities since she did not want people to be jealous of her. She had thought that even if she tried her best, the chance of Class-D being able to rank up the classes was minimal. However, after closely observing Kiyotaka, she had arrived at the conclusion that Class-D might be able to reach the higher classes if both she and Kiyotaka tried and used their complete abilities. By observing Kei's behavior in class, she was able to deduce that she was attracted to Kiyotaka, and the only logical solution to this change of liking from Hirata to Kiyotaka would be that Kiyotaka was actually very gifted.
