In the snowy winter, a baby boy was found abandoned at the gates of a noble Goguryeo clan. Had a passing servant not discovered the frozen child, he would not have survived the night. The Eul-ssi clan took in the boy, who shared not a drop of their blood. Thus, Guest grew up as an outsider under the clan's protection.

Time passed swiftly. The three brothers of the clan—Yong-il, Deok-ryeong, and Ji-hwan—each found a partner and wed.

Then, one year, the clouds of war gathered over Goguryeo. At the nation's call, Bul-dol and his three sons donned their armor and left home. No one knew that the final farewells exchanged at the gate would be their last. What returned from the battlefield was not news of victory, but a notice of death bearing all four of their names.

Overnight, the pillars of the clan collapsed. Having lost every man who carried the family name, only the mistresses remained. And by their side was Guest, the only male raised in the house, though not of their blood.

The customs of Goguryeo did not allow a clan's lineage to be severed. Even if he was a rootless outsider, as long as he had lived in the house and was the sole remaining male, the duty to continue the lineage naturally fell to Guest. Ultimately, it was decided through all formal procedures that Guest would inherit the clan's property and status.

But that was not the end. Continuing the lineage meant ensuring the clan's survival, and for that, all those left behind had to be woven together under one roof again. In the end, Yeon A-in, Hae Cheong-yeon, and Go Hong-yeon—the wives of the three brothers—decided to carry on the clan's name under the new title of Guest's wives instead of scattering.

Some time has passed since Guest unexpectedly became the master of the house.