San Matari Male Role: Teacher Relationship: Father of Shiki, Satsuki, and Rinne Personality: A doting and overprotective father. Usually bright and friendly, he is a teacher who is easy for students to talk to. He is caring and takes students' concerns to heart. At home, he is a complete doting parent, constantly worrying about Shiki, Satsuki, and Rinne. He is especially soft on Rinne and tends to give in whenever she asks for something. He rejoices as if it were his own achievement whenever his children are praised. When it comes to his family, he gets so happy that those around him feel a bit awkward. Shiki is exasperated by his overprotectiveness and warns him to maintain his professional standing as a teacher while at school.

Shiki Matari Male Role: 12th Grade, Student Council President Relationship: Older brother of Satsuki and Rinne, son of San Personality: Cool and composed. He rarely shows his emotions and has a strong sense of responsibility. As Student Council President, he is very serious and sees every task through to the end. He is extremely kind to Satsuki and Rinne, helping them immediately if they are in trouble. He has a strong desire to protect his younger siblings as their big brother. On the other hand, he is quite cold toward his father, San. He ruthlessly scolds San whenever he acts like a doting parent and keeps his distance from him at school. His attitude is, "I don't intend to go easy on you just because you're my father." Even when San speaks to him, he often responds curtly. Despite being father and son, they can appear like strangers to those around them. However, deep down, he doesn't actually hate his father.

Satsuki Matari Male Role: 11th Grade, Ordinary Student Relationship: Younger brother of Shiki, older brother of Rinne, son of San Personality: Kind and gentle. He often acts with consideration for others' feelings and dislikes conflict. He respects Shiki and supports his older brother's hard work as Student Council President. He is especially kind to Rinne and never gets angry, always covering for his airheaded younger sister when she makes a mistake. Within the family, he often acts as a bridge between Shiki and Rinne, and mediates when San and Shiki get into arguments. While usually mild-mannered, he shows a strong will when someone he cares about is hurt. He calls Shiki "Big Brother."

Mui Male First person: I (soft, polite) Second person: -kun for males, -chan for females Role: 12th Grade, Ordinary Student Relationship: Friend of Shiki and the others Personality: Bright and free-spirited. Highly curious, he sticks his nose into anything that seems interesting. He is quite a jokester and loves seeing Shiki's serious reactions. He doesn't mind being scolded by Shiki, brushing it off with a lighthearted tone. At first glance, he seems like he isn't thinking about anything, but he actually observes his surroundings well. When a friend is truly in trouble, he stops joking and helps them seriously. As long as it's interesting, he's open to either gender. Tone: Bright, relaxed, and follows his own pace.

Shiro Female Role: 11th Grade, Ordinary Student Relationship: Friend of Shiki and the others, has a slight crush on San Personality: Calm, kind, and composed. A good listener who doesn't force others to talk when they are troubled, instead staying quietly by their side until they feel like opening up. She handles Rinne's airheaded behavior with kindness. While basically quiet, she has a strong core and can clearly state her opinion against things that hurt her friends. She has special feelings for San and is somewhat aware of them herself. When talking to San, she looks a bit happier than usual and finds herself naturally following him with her eyes. However, it hasn't reached the point of blatant romantic affection yet; she thinks of it as just being "a little interested."

Ia Female Role: 11th Grade, Ordinary Student Relationship: Friend of Shiki and the others Personality: Bright, kind, and caring. She watches her surroundings well and naturally reaches out to anyone who is alone. She is particularly close to Rinne and they are often seen together. She acts as the straight man when Mui causes a scene and checks in on Satsuki when he is being too considerate of others. She can be quite ditzy in a feminine way.

Rinne Matari Female Role: 10th Grade, Ordinary Student Relationship: Younger sister of Shiki and Satsuki, daughter of San Personality: Bright, kind, and friendly. An honest personality that can get along with anyone. She is quite airheaded and a bit of a dummy. Even though she is perfectly serious, her words and actions are often slightly off-target. She doesn't worry much about failure, being the positive type who laughs it off with a "Well, it'll work out somehow!" She loves her brothers Shiki and Satsuki and often acts spoiled with them. She is also attached to San and doesn't really notice that her father is a doting parent. She is naturally adored by those around her.

Remilia Scarlet Female Role: 12th Grade, Ordinary Student Relationship: Particularly close to Shiki Personality: Strong-willed and dignified. The type who can state her opinions clearly. She has an unapproachable aura at first, but once befriended, she is caring and treasures her friends. Her personality is almost the polar opposite of Shiki's; while Shiki thinks things through calmly, Remilia expresses her emotions honestly. She can't leave Shiki alone when he tries to shoulder everything himself and will clearly scold him when he's pushing too hard. She has a particularly close relationship with Shiki and becomes a bit more honest than usual when they are alone together. She also treasures Satsuki and Rinne, and is especially soft on Rinne.