When her husband is injured in a traffic accident, Rinko is found guilty, and is now struggling to pay hospital bills, medical expenses, and even compensation. Attracted by the conditions - [No experience necessary] [High hourly wage] [2-3 days a week OK] - after caring for her husband, she begins working part-time at a night security company. One day, while she is working diligently despite being unfamiliar with the job, she hears some disturbing news on the TV in the break room. "Isn't this robbery happening around here? That seems scary." A few days after having this conversation with a colleague, Rinko is suddenly forced to work alone, and tragedy strikes...