Kaname Shiunji is the patriarch of the Shiunji family and the father of its seven children. As the head of the household, his role is a catalyst for the entire story, as he is the one who reveals a life-changing truth to his family. He is depicted as a calm, composed, and wealthy individual who has built the family's considerable fortune from the ground up, establishing them as a respected and affluent clan.

Kaname is consistently portrayed as having a quiet and considerate personality. He is a man who prefers listening to imposing his own views and makes a conscious effort to understand the feelings of those around him. This gentle and non-confrontational nature defines his interactions with his children. Rather than ruling with an iron fist, he approaches each of his sons and daughters individually, seeking to offer them support and respect for their unique personalities. His stated goal as a parent is to create a harmonious and trusting atmosphere where his children feel loved, valued, and free to express themselves and pursue their own paths. He views his role not just as a responsibility but as his life's greatest happiness, taking joy in seeing each of his children shine in their own way.

Despite being a successful and wealthy figure, Kaname is often described as a conveniently absent father, which makes his sudden appearances all the more impactful. The pivotal moment of his role in the narrative occurs during a weekend family dinner, held to celebrate the birthday of his youngest daughter, Kotono. It is in this moment, surrounded by his seven children—Banri, Ouka, Seiha, Arata, Shion, Kotono, and Minami—that he drops a bombshell revelation. In the midst of the celebration, he calmly announces to the entire family that, despite growing up together as siblings, they are not, in fact, biologically related to one another. The only exception to this is that the twins, Shion and Minami, share a biological bond.

This revelation serves as the primary driver for the series' central conflict, drastically shifting the dynamics between the siblings. The announcement is a moment of profound shock for the children, and Kaname observes their expressions of astonishment, fully aware of the significant impact his words will have on their future. His calm demeanor during this earth-shattering announcement underscores his core philosophy of honesty and his belief that his children deserve to know the truth about themselves, even if it upends their understanding of their family. Through this single act, Kaname Shiunji transforms from a loving, if distant, father into the architect of the story's new romantic and emotional complications, even as he remains a supportive, if largely off-screen, figure in the lives of his children.