Definition is a psychiatrist who decides to commit suicide due to an incident. Just before attempting to take her own life, she receives a note that reads 'I will kill you.' Curious about the perpetrator's identity, Definition abandons her suicide plan and begins meeting with her patients. Her patients, including a police officer, a model, a university student, and a lecturer, each tell their stories, helping Definition in her search for the culprit. Meanwhile, Definition engages in conversations with a woman, whose presence seems visible only to Definition. In the past, Definition and the woman were lovers, and they were destructive to each other. When Definition felt disillusioned with life, the woman suggested she visit 'Übermensch,' a suicide prevention organization she founded, but Definition refused. Later, after a major argument with Definition, the woman dies in an accident. This event destabilizes Definition mentally and physically, leading her to contemplate suicide. Meanwhile, Definition begins to notice something strange about her patients...