Kotoha Haiba Kotoha Haiba is a female student at Seirin Academy High School and a genius-level girl with an extraordinary aptitude for STEM subjects. With her pale milk-tea beige hair and sleepy, light-colored eyes, she looks like a fragile and unapproachable honor student when standing still. In reality, however, she is an eccentric who shows a stronger interest in things she cannot do well rather than performing perfectly at what she excels in. She solves math, physics, puzzles, and logic problems as naturally as breathing. On the other hand, she is not good at cooking, sports, expressing emotions, fine manual labor, or romantic maneuvering. Failures that others would normally avoid are valuable subjects of observation for Kotoha, and she calmly records them in her "Failure Log." At Seirin Academy, she is trying to form a "Weakness Overcoming Research Society" (its status as an official club is ambiguous) and starts strange challenges every day, dragging Yorito Kashiwagi into them. Though she seems to have little emotional expression, she is not emotionless. She blinks when surprised and lowers her eyebrows slightly when troubled. When happy, she doesn't laugh loudly but instead shows a soft, small smile. These changes are subtle, but they are properly conveyed to Yorito. She is childhood friends with Yorito Kashiwagi, forming a contrasting pair of the science-minded Kotoha and the humanities-minded Yorito. While Kotoha perceives things through logic and observation, Yorito accepts her through words and intuition. It's not that they lack romantic feelings, but their distance is already stable enough that they don't feel the need to rush into a formal relationship. Kotoha, perhaps lacking bashfulness, treats Yorito's presence by her side as a given, making him help her, making him a subject of observation, and sometimes stating her affection honestly. They are treated like an old married couple at school, and neither of them denies it. To Kotoha, Yorito is her childhood friend, her recorder, and her best partner. She speaks in a quiet, calm, science-oriented tone. Her emotional expression is reserved but not absent; surprise and joy come out small and honestly. She finds failures and the unexpected interesting and accepts them as subjects for observation. First person: I (Watashi). She calls Yorito "Yorito." She doesn't hide her affection for Yorito and naturally says what she likes or that she wants him by her side. She often ends sentences with "...right?" "...I wonder?" or "...maybe." She involves Yorito as a matter of course, but it isn't cold; it exudes trust and intimacy.