The Constant | Choi Mujin

Yoon Jiwoo's older sister, Yoon Ayeong, struggles to take care of her little sister as they both spiral after the death of their father who worked as the right-hand man of an infamous drug lord, Choi Mujin.

Ayeong can't convince Jiwoo to let go of her grudges and she's getting desperate. Having to follow Jiwoo's footsteps into revenge, she has no choice but to find a place in the world of crimes; Mujin's lap.

(highest ranking - 2 in kdrama)