Whenever she tries to open the door on a hot day, Ye-rin who lives alone hears the man next door opening the door after her. She has no choice but to keep the air conditioner on and her electric bill comes as jolt. Whenever she tries to clean her room with the door wide open, she smells her neighbor’s cigarette smoke drifting into her room from the corridor. She is compelled to light a scented candle. She leaves a note on the wall asking him not to smoke in the corridor only to find the note meaninglessly fallen on the floor. As her patience is wearing thin, Ye-rin talks to the janitor about it but all she gets is a complaint from the man. She eventually stands up to him by opening the door wide.