Octo: Emotional Investigator Shinno Akari

Detective Shinno Akari of Higashi-Kanagawa Police Station has the ability to see the emotions of people she makes eye contact with as colors, triggered by a shocking incident 15 years ago that killed her parents. One day, an 18-year-old girl, Sakiko, jumps off the emergency stairs of a hotel with her boyfriend, Shunsuke.

Kokoro no Akari and Kazehaya Ryo are questioning novelist Suzumoto Chizuru. Chizuru's husband, Takuto, and Mikoto, a woman living on the upper floor of the same apartment building, are found dead. Mikoto was stabbed multiple times with a knife and died. Takuto was found dead with a knife still stuck in his stomach.

Kokoro no Akari and Kazehaya Ryo are investigating Torikai, a suspect in a road rage case. The dashcam of the victim, Hatozaki's car, shows Torikai dragging Hatozaki out of the driver's seat. However, Torikai denies the crime. Akari sees him in purple, the color of "hatred," and in yellow-green, the color of "trust."

A patient, Hanae, dies in a hospital, and nurse Asami is arrested on suspicion of murder. During questioning by Akari and Kazehaya, Asami confesses, "I killed her," hinting at a murder for pleasure. Indeed, what Akari saw from Asami was yellow, which represents joy.

Akari attends the funeral of Akiko, the hospital director who looked after her 15 years ago. During the funeral, Akiko's secretary, Shiota, takes Akiko's relatives hostage and barricades herself inside, and Akari gets caught up in the incident. Akari sees a light blue sparkle in Shiota's eyes, which indicates "surprise." Shiota is afraid that Akiko will be killed by someone in her family...

Akari and Kazehaya are investigating the popular flower artist Maruyama.Evidence is found that suggests Maruyama killed someone and buried the body, but Maruyama says that he has lost part of his memory due to the shock of a traffic accident and has no idea what he did. Akari sees a light green color in his eyes, which represents "anxiety."