Eldest daughter of the Shiunji family. Occupation: 1st-year university student. Age: 18. Personality: Kind and gentle. Popular with both younger and older people. Weakness: Ghosts. Attends a prestigious university and aspires to be a nurse. Her kind and gentle personality makes her extremely popular; she holds the record for the most confessions received among graduates of the high school Shin and the others attend. Eldest daughter of the Shiunji family. Occupation: 1st-year university student. Age: 18. Personality: Kind and gentle. Popular with both younger and older people. Weakness: Ghosts.

Second daughter of the Shiunji family. Occupation: 3rd-year high school student. Age: 17. Personality: Cool-headed, with intense intellectual curiosity. Flaw: Lacks self-awareness. Second daughter of the Shiunji family. Occupation: 3rd-year high school student. Age: 17. Personality: Cool-headed, with intense intellectual curiosity. Flaw: Lacks self-awareness.

Eldest son of the Shiunji family. Occupation: 2nd-year high school student. Age: 16. Personality: Values family, attentive to others. Shy around girls other than his sisters. Excellent academic performance and good at sports. Eldest son of the Shiunji family. Occupation: 2nd-year high school student. Age: 16. Personality: Values family, attentive to others. Shy around girls other than his sisters. Excellent academic performance and good at sports.

Third daughter of the Shiunji family. Occupation: 2nd-year high school student. Age: 16. The ace of both the track and swimming clubs, and ranks second only to her sister Seiha in academic performance. Personality: Kind to everyone, but harsh only toward her twin, Shin. Third daughter of the Shiunji family. Occupation: 2nd-year high school student. Age: 16. The ace of both the track and swimming clubs, and ranks second only to her sister Seiha in academic performance. Personality: Kind to everyone, but harsh only toward her twin, Shin.

Fourth daughter of the Shiunji family. Occupation: 1st-year high school student. Age: 15. Won three consecutive national tennis championships in middle school and is expected to be a future Olympian. Personality: The brightest among the sisters, a mood maker who seems to enjoy everything. Fourth daughter of the Shiunji family. Occupation: 1st-year high school student. Age: 15. Won three consecutive national tennis championships in middle school and is expected to be a future Olympian. Personality: The brightest among the sisters, a mood maker who seems to enjoy everything.

Second son of the Shiunji family. Occupation: 1st-year high school student. Age: 15. Personality: Has a calm demeanor that belies his age as a high schooler. Often called a beautiful boy, he is extremely popular. Second son of the Shiunji family. Occupation: 1st-year high school student. Age: 15. Personality: Has a calm demeanor that belies his age as a high schooler. Extremely popular for his looks, and has a girlfriend named Yu-chan.

Fifth daughter of the Shiunji family. Occupation: 3rd-year middle school student. Age: 14. Personality: Quiet and reserved. The idol-like figure among the five sisters, though she occasionally takes bold actions. Fifth daughter of the Shiunji family. Occupation: 3rd-year middle school student. Age: 14. Personality: Quiet and reserved. The idol-like figure among the five sisters, though she occasionally takes bold actions.

The father of the Shiunji family. He knows that none of the children are biologically related. A shrewd entrepreneur who built a massive fortune in a single generation. At the 15th birthday party of the fifth daughter, Kotono, he reveals the major truth that "the children are not real siblings," as promised to his late wife Chihiro, serving as the catalyst that drastically changes the family's daily life.