A series of consecutive murders targeting only drug syndicate dealers occurs. At the crime scenes, cryptic blood messages are left behind, and from eyewitness testimonies, the culprit is dubbed the "Red Coat Killer." As DEUS progresses with the investigation, a tragedy involving a young couple emerges, hidden within the events.
The episode is actually connected to the 2005 film ULTRAMAN2: requiem, which was cancelled. Yuuki Kuroda, who plays Kyosuke Agata in this episode, was originally cast in the film as Toma. This character was described as "a friend of the protagonist who withdraws from society after an earthquake and longs for the return of a deceased female friend." Later in the story, Toma was set to become the antagonist known as "Human Element".[2][3]
Although the casting for ULTRAMAN2: requiem had been finalised, the project was ultimately cancelled. While the series was in development, Kazuya Konaka contacted Kuroda again, resulting in his casting as Kyosuke Agata. Interestingly, Toma and Kyosuke Agata have something in common: they both struggle to accept the death of a woman close to them.
During the production of this episode, Konaka intended to incorporate elements from ULTRAMAN2: requiem. Similarly, Keiichi Hasegawa noted that he included ideas in this episode that he had wanted to explore since Yellow Eyes but hadn’t been able to use before.
Hasegawa explained that the episode was based on a concept he had previously developed for other projects. Since the main theme of the story was 'memory', which fit well with the series' worldview, he adapted the idea to match its style. Additionally, since the series was broadcast late at night, he was able to explore the concept in greater depth than in his original version.
Once it was decided that this episode would appear in the second half of the series, additional lines were added to emphasise Jin’s memory loss. In the scene where Asami casually eats with blood splattering on her face, the original script had the blood staining her white clothes. However, when it was discovered that Mahiru, who appears in episode 9, would also be wearing white, Hasegawa suggested changing Asami's outfit to a red dress and leaving the blood splatter on her face.
The name "Hupnath" comes from the word 'hypnosis', which refers to the act of inducing sleep or making suggestions.
In the theatre scene, the titles of Alfred Hitchcock' thrillers such as Psycho and Vertigo appear, and the episode’s plot was influenced by these films. Hasegawa explained that, in the world of the series, these film titles also existed, suggesting that closely related films are present in that universe.
At the end of the story, the blood-written word "notman" is revealed to be "Norman," referencing the Norman Bates name of Psycho. Constrained by a limited budget, Hasegawa crafted a more intricate plot, emphasising the impact of the final twist. Had "Norman" been read correctly from the outset, the mystery would have been lost. To preserve the suspense, the "r" was left unpronounced, causing viewers to misread it as a "t". However, this creative choice sparked debate during script discussions.
