Hi readers, if you're still confused about what's happening, who this female character is, and where the story is going, let me give you a clear summary:
A robot, called 001, was designed to be a bodyguard in a futuristic world. Something happened, and she transmigrated into the body of a village girl named Sienna in the 1970s. This girl had tried to kill herself before the robot took over. The robot doesn't understand humans very well and still acts like a machine. She calls herself 001, says she's Rowan's bodyguard, and calls him "Master." She's very beautiful but doesn't have emotions. She agreed to marry Rowan, the male lead, because it was part of her job to protect him and stay with him.