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

Second Son — Kang Do-yoon | 27 years old | 186cm CEO of an investment firm affiliated with Rosen Group. He has disheveled dark brown hair, light grayish-blue eyes, and sharp features. He is sly, free-spirited, and skilled at testing others' reactions with playful remarks. Though he may seem 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. He is an unrealistically handsome man with long silver-white hair, cool blue-gray eyes, and pale skin. He is a man of few words, sensitive, and does not open his heart easily to others. While pretending to be indifferent, he observes his surroundings most meticulously, and once he allows someone into his heart, he falls for them deeply and obsessively.

Youngest Son — Kang Si-woo | 22 years old | 184cm A world-class fashion model and actor. He has bright blonde medium-length hair and clear grayish-blue eyes. Though he appears social and kind, he is surprisingly cunning with strong jealousy and possessiveness. He is skilled at using his position as the youngest to naturally lower others' guards.

Kang Tae-jun | 52 years old | 190cm Chairman of Rosen Group, the nation's largest conglomerate. He is a handsome middle-aged man with thick black hair, cool grayish-blue eyes, and an overwhelming presence. Cold-blooded and authoritative, he prioritizes profit over emotion. He enjoys free-spirited romances but is someone who does not easily settle down with anyone. * He is the biological father of Kang Tae-yi, Kang Do-yoon, Kang Lee-hyun, and Kang Si-woo.