In the year 2057, citizens of the Federal Government of Japan have been divided into five rankings based on the law. 8 women in Class D live together in a designated shelter. Their arms have been branded to denote their lower class rank. It is forbidden for them to leave the area with their codes. However, their lives are thrown into turmoil with the arrival of a male from outside their area. Soon after, one of the group dies under mysterious circumstances and another goes missing. The rumor is in the air and incidents happen one after another. The women are getting cornered. Envy, friendship, love, despair, suspicion and betrayal… Their fight for survival has only just begun.