Iizawa Momo

They took her identity. They took her freedom. Now, in a man-made labyrinth of concrete and steel, where terrified young women are stripped of their pasts and humanity, she has been reduced to the level of prey. Prey for the ancient evil that lurks inside the walls of this penitentiary; an invisible hunter that stalks the halls of the damned, feeding on the tortured souls within. Against this unnamable horror, the inmate known as Sigma must face a fate beyond her worst nightmares; something far more terrifying than anything the brutal guards and corrupt wardens could imagine. Because unknown to them, Sigma has come to this place on a mission of her own. There's something far worse than death inside this prison, and it's waiting for FEMALE PRISONER SIGMA.

In Tokyo, prostitution in the name of "Enjo Kosai" is in fashion among some high school girls. A mysterious man Kuni lament such girls but cannot deny a strong desire for them. He punish the girls by having sex with them without paying them. He calls this operation "Stop the Bitch Campaign" for public justice. Working in a sex trade shop where abnormal people are satisfied with their lust. Aoi tries to find out the man who raped her desperately in the past. One day, Aoi meets Kuni.

Fuyuki witnesses Chihiro, an office lady, being groped on the train. In the confusion, he also touches Chihiro's body, but warns the culprit, Tamura, but he claims that he is innocent. Then Naho, who claims to be a lawyer, appears and shows him a photo on her cell phone that shows evidence...

Shūichirō Kiriyama works at the Limitation Task Force, the place where the cases which have reached the statute of limitations are destroyed. Getting bored of his job, he decides to find a hobby, because it seems important to him to have a hobby. So he decides to puzzle out the unsolved cases on his free time, helped by his coworker Mikazuki, who seems to have a crush on him.

Fujisaki Aya is a young college student whose family is 150 million yen in debt after her father's corporation went bankrupt. To earn the money, she enters the Hostess Grand Prix.