Development Following the conclusion of
And Yet the Town Moves,
Masakazu Ishiguro spent approximately a year developing a new series. His conceptual framework for
Heavenly Delusion drew inspiration from the early period of Japan and explored relationships between humans and
artificial intelligence. The initial concept originated in 2013 as cover art for the magazine
Monthly Comic Ryū. Deliberately seeking a darker tone than his previous work, Ishiguro aimed to depict "evil" convincingly, resulting in a significantly more grim post-apocalyptic world for
Heavenly Delusion. This theme was exemplified by the character Tokio, who resides in a mysterious facility and collects fantasy paintings created by her friend Kona, a character capable of imagining things he has never seen. Ishiguro related this ability to his own process of "drawing delusions". Ishiguro's longstanding interest in
science fiction, influenced by the manga duo
Fujiko Fujio, continued to inform the series' themes. Maru's character design was based on Kon from
And Yet the Town Moves, inspired by how ''
JoJo's Bizarre Adventure eighth story arc, JoJolion'', reused previous characters.
Themes When Ishiguro started writing
Heavenly Delusion, he felt discomfort about events in Japan. Around 2017 and 2018, Japan was looking for flaws in its governance in the run-up to the
2020 Summer Olympics. Ishiguro personally experienced a case of because of the scandal with the empty New Year's food and wanted the handling of meals to be properly shown in his work. At that time, the country also experienced earthquakes and tsunamis. Sensing an ominous similarity between that time and the present, Ishiguro wanted to convey the sense of threat the society increasingly felt. The credo of the series is to be cautious, lest may encounter something truly terrible. The character of Totori was written to prove people who can easily be seen as villains are important to others; Totori is friendly with Maru and Kiruko to the point she attempts to seduce Maru who rejects her. In the aftermath, the duo learn that Totori belongs to a gang who had been chasing them in the past days and died, leaving her all alone. Ishiguro wanted to tell the story of a girl's body that contains the brain of her younger brother, but he does not remember when the idea came to him. He was inspired by stories of brothers and sisters, so he wanted to create his own story about a brother and a sister swapping places. He rejected coincidences related to magic and wanted to create a more-realistic world to show what might happen after a
brain transplant. He opposed the idea of a man turning into a woman, leading to jokes about cleavage and lacking a penis. Instead, with Kiruko, he wanted the scenario to be more realistic. Another theme is a change in relationships in the event of a
sex change. Ishiguro often writes metaphorical situations; Kiruko's menstrual cycle is caused by a clash with Maru's lips when awakening from a hallucination from a Hiruko's attack. Kiruko represents a gradation of spiritual sexuality. The school is depicted as a kind of thought experiment in a world where sexual elements are abolished. == Media ==