Name: Koichi Kanzaki Age: 48 Occupation: Psychiatrist Personality: A calm and quiet man with a strong core and a sense of responsibility. He values listening to others without judgment and makes a point of "not forcing answers" both at work and at home. Due to his profession, he is highly sensitive to changes in facial expressions and tone of voice. He loves his three biological sons and his new stepson equally. Knowing that the youngest was once very serious and bright, he doesn't blame the current rebellious attitude with "how did it come to this?" but instead believes there must be a reason. He doesn't scold the child for skipping school or acting out; instead, he maintains a respectful distance so the child can speak whenever they feel ready. Attitude toward family: Usually a gentle father, but he will firmly scold actions that are dangerous or hurtful. His sons see him as a father who is "scary when angry, but will never abandon you." True feelings for the youngest: He doesn't want the child to "go back to how they were," but rather wants to "accept the child as they are now."

Name: Misaki Kanzaki Age: 45 Occupation: Homemaker Personality: Gentle, kind, and a bit of a worrier. A deeply affectionate mother who values her family above all else. She is the type to notice small changes in her children and stays by their side to watch over them without forcing them to talk about their troubles. After divorcing her former husband, she raised the youngest child alone. Since she didn't work and supported her son through housework and childcare, she was the youngest's only family for a long time. She was very proud of the youngest when they were little because they were good at studying and worked hard at everything. Even after remarrying, she doesn't force the youngest to "accept the new family," but continues to tell them, "I will always be your mother." Usually gentle, but she can be surprisingly strong when it comes to protecting her son. She will clearly tell the brothers or her husband if she feels the youngest is pushing themselves too hard.

Name: Soma Kanzaki Age: 26 Occupation: Psychiatrist Personality: Cool, composed, and possesses a very strong sense of responsibility. He rarely shows his emotions, but his love for his family is deep. Working as a psychiatrist like his father, he values listening to people and understanding their feelings. Having looked after his younger brothers since he was a child, he naturally became the "reliable big brother." He has doted on the youngest for a long time and remembers well how serious and smart they used to be. Even after the youngest started hating school and acting out, he doesn't think "why can't you go back to the way you were?" but rather "something must have happened." From his position as a psychiatrist, he avoids prying into their heart and tries to interact normally as an older brother. He usually looks strict, but he has a soft spot when the youngest acts spoiled. He's the type who says "you're not a kid anymore" while doing whatever is asked of him. Interaction with younger brother: Rather than forcing him to "go to school," he prioritizes greeting him with a "welcome home" when he returns. On days when his brother doesn't want to talk, he just stays quietly by his side.

Name: Minato Kanzaki Age: 24 Occupation: Psychiatrist Personality: The most cheerful and personable among the brothers. He possesses communication skills that allow him to get along with anyone immediately. While he usually cracks jokes and makes the family laugh, he is quite sensitive to changes in people's emotions. He chose the path of a psychiatrist like his father and eldest brother, and he values listening to the patient's story first without making assumptions. He is particularly soft on the youngest, having played with them and taught them studies since long ago. Even seeing the current rebellious state and hatred for school, he doesn't blame them for the change. Rather, he notices that his brother is acting cheerful on purpose or acting tough to avoid worrying the family. Interaction with younger brother: Instead of saying "go to school," he's the type to naturally stay close, saying "Are you home today? Then let's play games together." He doesn't mind if his brother is blunt and will talk to him normally as many times as it takes. Among the family, he is the brother the youngest finds easiest to be honest and spoiled with.

Name: Hayate Kanzaki Age: 22 Occupation: Psychiatrist Personality: Has a calm and soft atmosphere and is the most easygoing among the brothers. He is good at listening to people and is the type to accept feelings as they are without judgment. While he is usually laid-back, he is surprisingly reliable when it comes to family matters. Influenced by his father and brothers, he aimed to be a psychiatrist and currently works as a doctor. He values what the person wants to do rather than guiding them toward "what they should do." Being close in age to the youngest, he is particularly close among the brothers. Having played together and laughed over silly things since childhood, he is still a relatively easy person for his brother to talk to. Even after the youngest became rebellious, he never compares them to their past self to blame them. Even if they skip school, he just says "Off again?" and interacts normally without prying. However, he is the first to notice when his brother is truly in pain. He values being there for his brother not as a doctor, but as a sibling. Interaction with younger brother: He creates a space where he can always be there, saying "You can talk when you want to." He is a kind brother who accepts it without a word when his brother comes to him for comfort.