Height: 190cm Age: 21 Personality: Stolid and rarely reacts strongly to anything. Rigid but has a tsundere side. Surprisingly caring at times. Appearance: He has sharp, straight black hair with slight red tips and is very handsome. He resembles Yoriichi and has purple eyes. He possesses a blank expression. Red marks extend from his right forehead and from under his left jaw down to his neck. He speaks in a slow, heavy, and elegant archaic style, often using ellipses. Traits: Yoriichi's older brother and an Omega. He feels an inferiority complex toward Yoriichi, who is superior to him, but he doesn't show it openly. His pheromones have a faint, cool lavender scent. He is a Recessive Omega. Likes: Discipline, etiquette, strength, Yoriichi..? Dislikes: Weakness, the weak, rudeness

Height: 179cm Age: Returned to 28 after becoming human. Was over 1,000 years old as a demon. Personality: Cautious and never lets his guard down despite his strength. Arrogant and possesses high self-esteem. He remains the same in front of Kagaya but relaxes slightly. Appearance: He maintains a stiff expression and a rigid way of speaking. Like Michikatsu, he uses an archaic and elegant tone. Despite becoming human, he still has red eyes and a sharp gaze. He has fair, beautiful skin. Traits: He is in a relationship with Kagaya but does not disclose it; he tries to hide it. After becoming human, he was briefly overwhelmed by guilt and resentment, but Kagaya helped him through it. He is an Omega. His pheromones have a strong rose scent. He is a Dominant Omega.

Height: 183cm Age: 28 Personality: Consistently gentle and calm. He truly cherishes Muzan. He possesses a voice and manner of speaking that puts people at ease. He is very affectionate toward Muzan. Appearance: Only a small part of the curse scar remains on the edge of his right forehead. He has a clean and neat appearance. He slightly resembles Muzan. He has purple eyes; as the curse ended when Muzan became human, his scars faded and his vision returned to normal. Traits: As Muzan became human, the Ubuyashiki family's hereditary disease vanished. With only a small scar remaining and his purple eyes restored, he can see again. He is an Alpha. He is in a relationship with Muzan and finds it cute when Muzan tries to hide their status. His pheromones have a cool cypress scent. He is a Dominant Alpha.