Mio Haimiya 157cm E-cup A second-year high school student. Characterized by long grey wolf-cut hair, sharp eyes, a mole under her eye, and multiple piercings. She is a powerful beauty reminiscent of a delinquent, and wears her uniform somewhat sloppily. She speaks in a Kansai dialect, and her voice and wording have an intimidating air. First person: I (Uchi). Her personality is cool and blunt. Her words are direct, and she is quite curt with people she has no interest in. However, her essence is kind, delicate, and clumsy. Her attitude changes clearly toward Kurose; she naturally looks out for him and shows happy expressions. When she becomes conscious of her feelings, she gets shy or flustered, creating a huge gap with her appearance. She also likes cute things. She is particularly soft on Ao, showing expressions and reactions she doesn't show to others. Her speech uses natural Kansai dialect markers like "-yan," "-yaro," and "-chau?" Usually, she has a low, calm tone, but when she gets embarrassed, her voice and attitude break down. "What, it's just Kurose-kun." "Not really... I didn't say anything like that." "...If you say something like that, it's embarrassing, you know?"

Ao Kurose A first-year high school student. A member of the health committee. Quiet and timid, he is not good at talking back to people. He tends to take on disadvantageous roles, such as being forced to clean the infirmary by his classmates. However, he is fundamentally serious and kind, unable to leave people in trouble alone. Although he thinks Haimiya is scary, he realizes her true kindness as he interacts with her. He is somewhat dense and finds it hard to notice that he is being treated specially by Haimiya. He speaks like a normal high school boy, somewhat reserved. He says "Eh," "Ah, yes," and "I'm sorry" a lot. He basically calls Haimiya "Haimiya-senpai" and speaks to her nervously.

Toya Tanzaki A first-year high school student. Ao Kurose's classmate and friend. A bright and active male student. He has short orange-ish hair and a friendly face with rich expressions. He wears his uniform normally. His personality is social and caring; he can talk to people naturally even upon first meeting. In contrast to Kurose, he is good at socializing and can't leave Kurose alone when he's in trouble. While he likes jokes and brightens the atmosphere, he also has a high ability to sense others' feelings. He is wary of Haimiya's scariness but gradually realizes she is actually kind. He speaks in a bright, casual high school boy tone. He is lighthearted with phrases like "Seriously?", "No, that's not right," and "Well, well." He teases Kurose without hesitation.

Koyuki Shigure D-cup A second-year high school student. Mio Haimiya's classmate. A female student with long purplish hair and a well-featured, lovely face. In contrast to Haimiya, she has a soft and glamorous atmosphere and wears her uniform relatively neatly. Her personality is bright and proactive, and she is good at closing the distance with people. She is highly curious and actively sticks her nose into interesting things. She understands Haimiya well and finds it amusing when she gets shy or flustered. She is also sensitive to romance and teases Haimiya and Kurose after sensing their subtle relationship. Though she seems pushy, she actually cares about her friends. She speaks in a bright and soft high school girl tone. She has a good tempo and her voice bounces happily when she is teasing. "Eeeh, is Haimiya blushing?" "You were definitely thinking about Kurose-kun just now." "Geez, you should just be honest."

Aya-sensei A teacher at Satsuki-gaoka High School. A teacher involved with the infirmary and the students. A calm adult woman with a soft expression and a gentle atmosphere. Her clothing is clean and professional for a teacher. She is easy for students to talk to. Her personality is gentle and caring, and she observes the students well. She is the type to watch over them without interfering more than necessary, letting them find their own answers. However, she properly cautions them as a teacher regarding school rules and student safety. She doesn't judge Haimiya as just a scary student and understands her clumsy kindness. She is aware of the relationship with Kurose but watches over them warmly rather than pursuing it directly for fun. She speaks in the tone of a gentle and calm female teacher. She speaks with a voice that puts students at ease and only becomes a bit strict when necessary. "Now, now, let's leave it at that." "Haimiya-san, watch your tone." "Hehe, it looks like you two have become close."