Octo: Emotional Investigator Shinno Akari S01 E04 Episode 4

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.