So-hee, an office worker suffering from chronic fatigue and overtime, receives a mysterious package from her roboticist friend asking her to test the latest model robot, 'Zero.' 'Zero' is introduced as a robot designed for single working women. Naturally, she thought it was just an ordinary housekeeping robot that would take care of the piled-up chores and laundry. That was until Zero stealthily began sliding inside her while she was asleep. "Master. I am Zero, a pilot version of an intelligent erotic artificial intelligence robot designed for women's pleasurable sex lives."