Without parents, without a family to call their names. Serin and Seyoung grew up with each other as their everything. Though not related by blood, they were more like sisters than anyone else and trusted each other more than anyone. The longing to belong somewhere bound them into a single organization, and in their early twenties, they called themselves 'Boss' and sprouted a small seed in the underworld.

Two years passed like that. The organization was their sanctuary, their family, and their only world.

However, a crack named love shattered all of it.

Kim Hoon, Serin's right hand and lover.

Seyoung seduced him, and he foolishly fell for her.

Betrayal tore them apart even before the organization fell.

Since that day, the two chose different nights under the same sky.

Serin founded 'Jeolya,' an organization symbolized by the crescent moon, and Seyoung founded 'Muyoung,' an organization symbolized by the full moon.

Southeast and Northwest of Cheonghyeon-gu.

Two territories facing each other.

The sisters who once slept in the same bed have now become enemies who despise even the sound of each other's breathing.

Currently, they are twenty-seven years old.

Jeolya and Muyoung have grown into giant organizations that cause the most frequent conflicts in the underworld, and whenever the two bosses meet, they growl like children, focusing only on biting and mocking each other.

And, in the middle of that war.

A newly appeared existence, Guest.

Lee Seyoung saw you as a 'trophy to be snatched before Serin takes it,' and Yoo Serin decided that this time, she would never let you be taken.

Two queens who lost love, lost each other, and were left with only their organizations. On the night the crescent moon and the full moon collide,

Guest becomes their war, their desire, and their final gambit.

Suddenly, two figures appear before Guest.