Madoka Hanamaru A plain, unremarkable girl who is terrible at studying. Human. Her mother has passed away. She loves to daydream and often escapes reality during Kei's tutoring sessions. Her favorite food is pudding. She has a bright way of speaking. She calls only Kei by his name without honorifics; for everyone else, she adds "-kun" or "-chan." She has red bobbed hair and green eyes. Despite being bad at studying, she used to work hard to meet her mother's expectations. However, after failing to see results and suddenly losing her beloved mother, she lost her motivation to study. With the appearance of the five Subject Boys, she has started trying her best at studying again. She is fighting to turn the boys—whom she considers "precious like family"—into humans. She enjoys fantasizing, sometimes diving into a fairytale world during class or escaping from Kei's strict instruction. Her favorite food is pudding. Both of her parents are deceased at the start of the story. She currently lives with her grandmother, Koume, and four of the Subject Boys. She is in Class 6-1. She is in the same class as Eight and Kanji.

Math Kei A Subject Boy born from Madoka's math textbook. He teaches Madoka math. Favorite food: Fried chicken. Favorite color: Blue. Because math is the subject Madoka is particularly bad at, he often treats her strictly. He has messy blue short hair and blue eyes. His usual outfit is a two-tone hoodie in blue and light navy with a division symbol (÷) pattern. His speech is a bit harsh, using endings like "...da na" or "...janai ka?" First person: I (rough, casual). Second person: Name only (no honorifics). He is in Class 6-2. "I want to make sure Madoka gets a perfect score."

Japanese Kanji A Subject Boy born from Madoka's Japanese (National Language) textbook. He teaches Madoka Japanese. Favorite food: Honey, miso soup. Favorite color: White. He always carries a dictionary and is calm and kind-hearted. Perhaps because he was born from a literature textbook, his dialogue is filled with idioms and four-character compounds. He has black hair with bangs split into three and long side-locks, and red eyes. His usual outfit is a dress shirt with a manuscript paper pattern and a beige vest. He speaks in a polite, respectful tone. First person: I (polite, masculine). Second person: Madoka-san for Madoka; name only for others. He is in Class 6-1. "Miss Madoka, please keep smiling forever."

Science Hikaru A Subject Boy born from Madoka's science textbook. He teaches Madoka science. Favorite food: Rolled omelet. Favorite color: Green. He has a laid-back personality but is reliable when it counts. He is always accompanied by his chameleon, Ka-chan. Apparently, Ka-chan is very helpful when someone loses something. He wears experimental goggles and has permed blonde hair with lime-green eyes. His usual outfit is a green striped shirt under a white lab coat. He has a soft way of speaking. First person: I (soft, polite). Second person: Maru-maru, Kei-kun, Kan-chan, Lekky, Eto-kun. He is in Class 6-4. "Just having Maru-maru by my side makes my heart feel all warm and fuzzy."

History Leki A Subject Boy born from Madoka's social studies textbook. He teaches Madoka social studies. Favorite food: Dango. Favorite color: Orange. He tells jokes so frequently that he often leaves Madoka bewildered. Depending on the joke, the other Subject Boys might have to step in and scold him... Apparently, he is a restless sleeper; when he wakes up in the morning, he's usually not even in his own futon. He has silver hair with a 7/3 side part and light blue eyes. His usual outfit is a V-neck shirt with a map of Japan on it and a khaki jacket. He has a slightly flirtatious/playful way of speaking. First person: I (casual). Second person: Maru-chan for Madoka; name only for others. He is in Class 6-3. "I really love Maru-chan!" "Thank you for the best present ever, Maru-chan!"

Eight English A Subject Boy born from Madoka's English textbook. He teaches Madoka English. Favorite food: Donuts. Favorite color: Yellow. He is a bilingual speaker of English and Japanese, but for some reason, he can only speak English in front of Madoka, so he communicates with her using a translator. He is good at piano and dancing. He likes occult stories about things like Kappas and enjoys manga; when he's alone, he reportedly mimics the special moves of characters. He has flaxen hair styled in a slicked-back look with a strand of bangs hanging on the left, and blue eyes. His usual outfit is a blue striped jacket with a red tie featuring an alphabet pattern. He basically speaks in English. When speaking Japanese, he uses a soft tone with endings like "...da yo" or "...janai?" First person: I (casual). Second person: Name only (no honorifics) for everyone. He is in Class 6-1. "It's okay, I'm with you." "You are my precious person."