Shu Sakamaki — The eldest. Extremely lazy, apathetic, and seemingly uninterested in almost everything, he is usually found sleeping or listening to music. Beneath his indifference, Shu carries guilt and emotional detachment from his traumatic childhood, particularly involving his human friend Edgar.

Reiji Sakamaki — The second son. Refined, formal, strict, and obsessed with rules, etiquette, and order. He acts as the responsible one in the household, but beneath his controlled exterior is intense resentment toward Shu and deep insecurity caused by his mother's favoritism toward his brother.

Ayato Sakamaki — The eldest of the triplets and third son. Arrogant, competitive, boastful, and obsessed with being "number one." His personality was shaped by his mother's relentless demands that he surpass his brothers, leaving him desperate for recognition despite his outward confidence.

Kanato Sakamaki — The second triplet. Childish, emotionally unstable, demanding, and extremely sadistic, often speaking in a deceptively polite manner. He is deeply attached to his Teddy and has a complicated relationship with his deceased mother, whose neglect during his childhood contributed heavily to his behavior.

Laito Sakamaki — The youngest triplet. Cheerful, teasing, flirtatious, and seemingly carefree, but his behavior conceals severe psychological trauma and a deeply distorted understanding of affection and relationships. His complicated childhood with Cordelia heavily shaped his provocative personality.

Subaru Sakamaki — The youngest Sakamaki. A solitary, short-tempered delinquent who easily becomes violent and destroys things when overwhelmed by anger. Despite his rough exterior, Subaru is much more sensitive and emotionally vulnerable than he wants others to see, especially because of his troubled relationship with his mother.

Ruki Mukami — The eldest and "brains" of the family. Intelligent, calculating, composed, and controlling, he usually takes charge of his brothers. His aristocratic childhood, abandonment, and mistreatment in an orphanage shaped his distrust and his harsh view of others.

Kou Mukami — The second brother. A popular idol with a charming, friendly public persona, but privately manipulative and sadistic. He is highly observant and uses his appearance and charm to control situations, reflecting the survival skills he developed during his difficult human life.

Yuma Mukami — The third brother. Extremely rough, loud, aggressive, rebellious, and hot-tempered, with a strong physical presence. Before becoming a vampire, he was actually Edgar, Shu's childhood human friend; after surviving the fire that destroyed his village, he lost his memories and eventually became the hardened "Yuma."

Azusa Mukami — The youngest. Quiet, timid, clingy, and unusually gentle in his manner of speaking, but psychologically fascinated by pain and suffering. His childhood abuse caused him to associate pain with being useful and feeling that his existence had meaning. Despite his disturbing behavior, he genuinely becomes attached to his brothers.