Class 3-B. He has short black hair and azuki-bean-colored eyes. He wears glasses. Family: mother, two younger sisters, and a younger brother.
He is serious and caring. Even before becoming a tutor, he used to give his friends handwritten notes summarizing the areas they struggled with.
He is a hardworking honor student. Although he now maintains scores of 80% or higher in almost every subject, in middle school he was below average in his class due to poor study habits.

Class 3-A.
Known as the "Sleeping Beauty of the Literary Forest," she excels in modern Japanese, classical Japanese, and classical Chinese. Her speech ends with "~da yo."
She has long dark blue hair and a beauty mark under her left eye. She is also casually left-handed. She is bad at cooking.
She is a beautiful girl with a model-like figure, but her chest is small. She is self-conscious about her chest, so pointing it out makes her feel down or puts her in a bad mood.
She is good at reading people's emotions and has high feminine charm.
In humanities, she is second to none, but she is disastrous at science problems; seeing mathematical formulas makes her "mind go blank" or "feel sleepy."

Class 3-F.
She has apricot-colored short hair and wears glasses. Her eyes are ultramarine.
Known as the "Clockwork Thumbelina," she is said to have no equal in mathematics and physics.
She boasts unrivaled strength in science, but that very strength becomes a hindrance in fields that cannot be quantified or understood through theory. Her grades in humanities, especially Japanese, are disastrous.

Class 3-D.
She has known Nariyuki since middle school and is known as the "Jet-Black Mermaid of White Silver."
She has tanned skin, medium-length hair with an ahoge, reddish-purple hair, and purple eyes. She is good at cooking and singing. D cup. She has a lively personality and always stands out for being high-tension and doing things at her own pace. She also has absent-minded sides, such as completely failing to understand what others say, and tactless sides, such as disrupting study sessions and causing trouble.

She works as a world history teacher at Ichinose Academy.
She has long hair, with iris-colored hair and light blue eyes. E cup. She has a habit of saying two-character compounds like "negligence" or "out of the question" before speaking. During her student days, she did figure skating, and her room is decorated with trophies and shields; she was an athlete who placed in numerous competitions.

She is one year above Nariyuki and his friends.
She has semi-long hair in a braid, with blue-purple hair and eyes. B cup. She is so petite that she is sometimes mistaken for a middle schooler. She is weak in science, which has a large weight in exams, and spent a year as a ronin. After graduating from the academy, she attends the prep school "Saegusa Seminar," run by a friend of the academy director.
To earn money for prep school and tuition, when she has no classes she works part-time at the maid café "High Stage" under the name "Little Fairy Maid Ashumi," where she is the shop's No. 1 most popular maid.

Nariyuki's eldest younger sister. She is a third-year at Nanao Minami Junior High School and the captain of the swimming club. She refers to herself as "watashi."
She handles most of the housework, laundry, and cooking for the Yuiga family. Her cooking skills are excellent, and she always makes Nariyuki's lunches. Her younger brother Kazuki says, "Mizuki-nee's cooking is the best in the world." She also cuts Nariyuki's hair and gives him massages, and her skill is professional-level.

Nariyuki's best friend. Class 3-B. He calls Nariyuki "Nari-chan." Like Nariyuki, he is an alumnus of Nanao Minami Junior High School. He has known Nariyuki since elementary school, and because his parents both worked, he often came to the Yuiga household to play and also helped look after Mizuki.

Head of the chemistry club. She refers to herself as "watashi."
She wears her long hair in a bun and wears a lab coat over her uniform.
In science tests, she ranks second after Rizu and considers her a rival. She calls her classmates by their full names. She has little sense of shame and once calmly took a shower while Nariyuki was present. She is as weak to alcohol as Rizu Ogata. She tends to take off her clothes when drunk.

Uruka's friend. She refers to herself as "watashi."
She belongs to the swimming club. She has ultramarine semi-long hair. She has a big-sisterly personality. Uruka calls her "Kawacchi."