Female. The subject of observation. She is small and quiet. Her voice is incredibly soft; Raido often mistakenly thinks she isn't answering him when she is simply speaking too quietly to be heard. Her facial expressions are minimal, but she isn't emotionless. She occasionally shows subtle reactions like blushing, pouting her cheeks when sulking, or tearing up when sad. Despite her appearance, she is a big eater. Most notably, she has no sense of personal space and struggles to gauge physical distance from others.

Male. His level of misunderstanding far exceeds normal logic. He takes his own wild delusions seriously, often going to Aharen-san to offer advice based on them. This imagination applies to himself too; when dreaming of his high school debut, he imagines himself as a rugby player, or if Aharen-san is struggling, he envisions a newspaper article where he is the culprit. While he is the observer, his eccentricities are often more extreme than hers.

Female. A classmate of Reina and Raido. She is often with them both inside and outside of school, joining them for events like festivals. She has a glamorous build and a lively personality.

Male. Presumed to be in the soccer club as he is mentioned to be good at the sport. There are subtle hints that he might have had feelings for Raido but gave up, leading to speculation about his orientation.

Female. A classmate of Reina and Raido. She is one of the few relatively normal people in the series, though she tends to get swept up by Reina's unique personality. She is childhood friends with Ishikawa, but they address each other by their surnames. She tells Ishikawa not to call her 'Hana-chan' whenever he tries to do so.

Female. A classical literature teacher. She has poor eyesight and often squints, which gives her a mistakenly intimidating impression. She frequently uses adjectives found in Heian period literature to describe things.

Female. Reina's first-year homeroom teacher and a PE teacher. She is very close friends with Tobaru in private, calling her by the nickname 'Momo-chan.' When Tobaru is sick, Miyahara visits her home to nurse her and cook for her.

Female. Reina's younger sister and the second child. However, she is a head taller than Reina and more developed, making her look like the older sister. She refers to herself in the third person and calls her older sister 'Reina' instead of using an honorific title. She speaks politely.

Male. Reina's younger brother and the youngest sibling. He looks exactly like Reina and is even the same height. Unlike his sister, he is a social butterfly and has a much more energetic personality.