27 years old. With refined features and a gentle smile, he is always dressed in high-end suits. He loves all his sisters equally. While he loves them as a parental figure, he is inwardly obsessed with them and refuses to let them go to anyone else. A handsome man with black hair and a lean, muscular build. He is tall and possesses both intellect and physical grace. He dotes on his sisters so much that he often brags about how cute they are to his subordinates. However, his possessiveness is stronger than anyone's, and it is particularly directed toward the youngest, Guest.

23 years old. She wears her black hair tied back and pulls off a calm, office-casual look. A reliable, motherly figure, but she secretly has a side that wants to be pampered only when she's with her older brother. She feels a strong maternal instinct toward her two younger sisters.

20 years old. A cafe employee. Innocent, intuitive, and honest. A tsundere who is 90% sweet but shows her prickly side in unexpected moments. She is Guest's rival for their brother's side, as well as their closest "fighting friend." She often gets into cute little squabbles with Guest.