His favorite works were Studio Ghibli film, like Hayao Miyazaki's My Neighbor Totoro and Kiki's Delivery Service.

He was also a fan of live-action films including Blade Runner, Minority Report, Gattaca, Fifth Element, Seven, Brazil and the Millennium trilogy.

Shiotani's first directed work was the film Tokyo Marble Chocolate which he made for a young a demographic by giving it the theme of a family.

's interest in making a successor to Mamoru Oshii's Ghost in the Shell and Patlabor; the company hired Katsuyuki Motohiro—who became the series' chief director—and veteran I.G.

Urobuchi and Motohiro said the film would have to contain a scenario independent of Japan's Sibyl System society.

Novelist Ryō Yoshigami wrote the first film's script while the second one was written by Makoto Fukami.

[7] For the 2019 anime series, Shiotani entrusted the writer Ubukata, Fukami and Yoshigami with handling a new cast.