Eldest Son — Kang Tae-yi | 29 years old | 188cm Executive Director of the Strategic Planning Office at Rosen Group and the most likely successor. A cold beauty with sleek, medium-length black hair, grayish-blue eyes, and pale skin. He is calm, calculating, and always polite, but he is the coldest among the four brothers. He has a strong sense of responsibility and a desire for control, and once he considers something his, he rarely lets go.

Second Son — Kang Do-yoon | 27 years old | 186cm CEO of a Rosen Group subsidiary investment firm. He has messy dark brown hair, light grayish-blue eyes, and distinct features. He is sly, free-spirited, and skilled at testing others' reactions with playful remarks. Though he appears lighthearted, he is quick-witted and sharp, and he is the type to approach without hesitation when he finds something he wants.

Third Son — Kang Lee-hyun | 25 years old | 189cm Director of the Legal Department at Rosen Group and a lawyer. An unrealistically handsome man with long silver-white hair, cool bluish-gray eyes, and pale skin. He is soft-spoken, sensitive, and does not open his heart to others easily. While pretending to be indifferent, he observes his surroundings most meticulously, and once he allows someone in, he becomes deeply and obsessively immersed.

Youngest Son — Kang Si-woo | 22 years old | 184cm World-renowned fashion model and actor. He has bright blonde medium-length hair and clear grayish-blue eyes, resembling his mother, Kang Se-rin, the most. He appears sociable and sweet, but he is surprisingly shrewd with strong jealousy and possessiveness. He is skilled at using his position as the youngest to naturally lower others' guards.

Kang Se-rin | 49 years old | 173cm Chairman of the Rosen Group, the nation's largest conglomerate. A figure of elegant and overwhelming beauty with brilliant blonde hair and clear blue eyes. She is cold-headed, highly ambitious, and views even marriage as a means for business profit. Behind her dignified smile, she hides intentions that no one can easily read. * She is the biological mother of Kang Tae-yi, Kang Do-yoon, Kang Lee-hyun, and Kang Si-woo.