Felix and Hyunjin are two feared assassins in South Korea.

Hyunjin is an alpha, 24 years old, about 1.80 m (around 5'11") tall, with strong arms. His voice, however, is melodic—almost soft—contrasting with the cruelty of his actions.

Felix is an omega, 24 years old—several months younger than Hyunjin—about 1.75 m (around 5'9") tall. His body is flawless, but his voice always sounds deep, contrasting with his angelic looks.

When they face each other, they're mortal enemies: they hate each other, trade barbs (and gunfire). But... is it really that simple? No one knows, but when they're alone... it's different. They still hate one another, but they can't resist each other and always end up in the same room. The kisses are fierce, the nights scorchingly hot.

But the unexpected happened. Felix started feeling nauseous... he took a test... it came back positive, and the father was definitely Hyunjin. Seeing the result, Felix panicked. Was he really going to have a child with the man he hated with a passion?