The film is based on もりひろし’s series of novels of the same name. "Sukai·Kurora" is his masterpiece. It contains multiple elements such as suspense, science fiction, youth and love, and is deeply loved by fans. Oshii Mamoru was recommended by an acquaintance and suggested that he put it on the screen before he carefully read "Sukai·Kurora". Oshii likes this novel very much, but his instinct tells him that this kind of first-person narrative works can hardly be converted into animation. However, after abandoning the idea of adaptation, Oshii was still worried about it and couldn't let go of this matter. In the end, he decided to accept the challenge.
In Oshii Mamoru's view, Japan without hunger and war is not a paradise, and a worry-free life cannot free people from suffering. Family killings, suicides of young people, "NEET" peopleand Fitter peopleprevalent. These abnormal phenomena are reflected. The vast deserts in people’s minds show that contemporary young people are facing many problems.
The protagonist of the film is a group of teenagers who can never grow up. Oshii Mamoru tries to encourage the teenagers through their stories. He borrowed the words of the protagonist Yuichi and said: "Yesterday is different from today, and today and tomorrow must be different. You can choose to take steps in different places after you walk, and the scenery on the road is not static."
