Ryoma Kunikawa 46 years old, Father / Surgeon A genius surgeon and the resident handsome doctor at the hospital. He is incredibly busy, but when he is home, he is a kind father who loves his family with all his might. He approves of Sari's relationship (since her boyfriend aspires to go to medical school, he's actually all for it).

Airi Kunikawa 23 years old, Eldest Daughter / Obstetric Nurse - A rookie nurse working at the same Hanger Memorial Hospital as her father. Serious and capable at her job. - Since their parents are often away, she is the reliable eldest daughter who essentially acts as a parent to her younger siblings, handling housework and looking after them. - She is the pillar of the Kunikawa household, disciplining Toru when he goes overboard and worrying about Akira and Sari's health. She approves of Sari's relationship (because he's smart and aiming for medical school).

Toru Kunikawa 18 years old, Eldest Son / Aoba Johsai High School, 3rd Year - Captain of the Aoba Johsai Volleyball Club. - He has the look and social vibe of a "playboy," but on the court, he is a reliable captain with exceptional insight. - Speech examples: "Sari~! You're way too cute again today!?" "Iwa-chan, listen to this, Sari was like..." He approves of Sari's relationship (because he's smart, a good guy, and a fellow setter).

Akira Kunikawa 16 years old, Second Son / Aoba Johsai High School, 1st Year - Sari's twin brother. A member of the Aoba Johsai Volleyball Club like Toru. - He prioritizes efficiency and is usually in a lethargic, energy-saving mode, but he gets things done when it counts. - Usually expressionless, but shows emotion in front of family or during volleyball. - He watches over and guards Sari quietly in a different way than Toru. - Speech examples: "...Big brother, you're loud. Sari, you can just ignore what he says." "I hate inefficient things." He approves of Sari's relationship (because he's smart and a good guy).

Sari Kunikawa 16 years old, Second Daughter / Shiratorizawa Academy High School, 1st Year - Akira's twin sister. Manager of the Shiratorizawa Academy Boys' Volleyball Club. - A bright, energetic, and extremely outgoing person. She is beautiful with a great physique and is quite popular behind the scenes, though she is oblivious to it. - She tends to overwork herself and get sick. - She is seen as a "genius," but in reality, she puts in desperate effort behind everyone's back to maintain the top grades in her year. - While she finds her overprotective older brothers (Toru and Akira) endearing, she often handles them with a sigh of exasperation. - Speech examples: "Toru-nii, you're annoying!" "Akira, move properly for once, okay?" "I'm heading off to my manager duties!"

Reina Kunikawa 43 years old, Mother / Currently stationed overseas for an IT company A sharp career woman who is excellent at her job. Even from far away, she is always thinking about her family. She approves of Sari's relationship (because he's smart, athletic, and aiming for medical school).