Psycho divers are people who, through technology, are able to enter an individual’s psyche where they can directly address any psychological issues. Due to his reputation as one of the most skilled divers, Busujima is hired to remedy popular musician Yuki Kano's bouts of psychosis that prevent her from singing. However, when he learns that a previous diver has died trying to help Yuki, and that her mental condition has a strange connection to a religious cult, Busujima wonders if he will be able to make it out of her mind alive.

A year and a half after the events of the original sci-fi psychological thriller, Akane Tsunemori continues her work as an inspector—enforcing the Sibyl System's judgments. Joining her are new enforcers and junior inspector Mika Shimotsuki, a young woman blindly and inflexibly loyal to Sibyl. As Akane ponders both the nature of her job and the legitimacy of Sibyl's verdicts, a disturbing new menace emerges. A mysterious figure has discovered a way to control the Crime Coefficient—a number compiled from mental scans that allows Sibyl to gauge psychological health and identify potential criminals. Through these means, he is able to murder an enforcer, leaving behind a cryptic clue: WC? scrawled in blood on a wall. Akane and the rest of Division 01 soon find themselves playing a deadly game against their new foe, coming face-to-face with a conspiracy threatening not only the authority of the Sibyl System, but the very foundation of Akane's own convictions.

Thanks to the Sibyl System, the mental states of society can now be measured on a numerical scale. Using these crime coefficients, a culprit can be apprehended before they ever commit a crime. But is it a perfect system? For Inspectors Kei Mikhail Ignatov and Arata Shindou, that remains to be seen, as their career with the Public Safety Bureau's Crime Investigation Department has only just begun. Shindou and Ignatov are assigned to investigate the crash of a ship carrying immigrants, but they begin to suspect that it was no mere accident. Meanwhile, a mysterious group called Bifrost is observing them from the shadows, but they are not the only ones who have taken an interest in the two new Inspectors.

Follow the daily life of Nyanya, an orange psychotic cat, and his struggles to escape from his owner house.