Choi Ji Young who is a workaholic is a female lead. Her boyfriend wants to take a trip with her but she doesn't want because she only focus on her work. 

She should turn off all lights if she leaves work. So, she tried to turn them off but she fell and blacked out for a while. Just then, one bulb flickered as well. 

She was afraid of blinking her eyes as the bulb was also blinking. She realises the bulb and her connect with each other and she must die to turn off the light.