I don't necessarily think that fans of the unique "Zero" series, which has been beloved silently since the good old days of consumer game consoles and for certain reasons never had media tie-ups, wanted it to get a novel or movie. As one of the people involved in the movie behind the scenes, I'm sorry for that. But for me, a big issue was to transform something important to fans and the creators into a movie without destroying it. Happily, I should perhaps say, lots of things happened to made a direct movie adaptation difficult, including the in-development newest game (most of my work involved talking about the media mix and things like that), and as a result we had to make another "Zero" that didn't exist anywhere else.
However, for the game's development team and I, as well as the director, that wasn't a bad thing at all. As I chatted to the game's developers, we spoke of several old movies and shojo manga that I hadn't expected. For example, Peter Weir's Australian movie "Picnic at Hanging Rock" came up right away when we were initially thinking about what kind of movie to make. The developers had been looking around here and there for things that had themes like spiriting aways, the mayoiga and things in Kunio Yanagita's "Tono Monogatari" to put in there, and I thought of it right away. It's apparently based on a true story where three girls and their teacher go to a rocky mountain for a picnic and disappear, and only one comes back (though it actually looks to be fictional), that was released in the mid-80s in Japan. I was still young at the time, and it really brings back memories. So maybe, if you've read the novel and might be wondering why two girls died and one came back alive, that's why. We also said wel iked the idea of a story set at a girls' school dorm, so we talked about another old movie, "Summer 1999", directed by Shunsuke Kaneko. It's set in a German gymnasium and based on Moto Hagio's "Thomas no Shinzo", but it was a weird film, moved to Japan and having all of the boys played by girls dressed up as boys. Then we also talked about things like Akimi Yoshida's "The Cherry Orchard" repeating the same thing every year, and Yumi Shirakura's "Reading Story", and got a bunch of things that fitted the same kind of image, and started to get a clearer image of the other "Zero" that the development team wanted. I was pleased that it wasn't too far away from my own image.
When I was told that the new game's image was based around water, I took "water" and "girls" and did some research on Shinobu Orikuchi's "water woman", aka "bride of god", decided on a plot about girls who become a girl's "bride of god", decided to use Millais' painting of Ophelia, and have them sing Ophelia's poem from Mori Ogai's Omokage at their graduation. It was also not my wish but the director's that certain characters should have a cameo appearance in the film.
When I began to write the novel, instead of having an image board for several scenes I instead used Yumi Shirakura's short paragraphs, which were also used as reference for the director making the film. When I got stuck, I came upon bizarre illustrations on the site of Foo Swee Chin (hence my asking her to do the illustrations).
And that is how this book came about as a basis for the film; a "Zero" that is also not "Zero". I'm glad that I got to help out in giving this "other Zero" form, that was secreted away inside the developers' hearts, to the fans.
By the way, I didn't give my opinion for casting, but for me the headmistress is Nae Yuki, the nun is Chiaki Kuriyama, and Mary is Aya Hirano. I wrote them with that image in mind. That part alone is my hobby. I mean, they're the actress from my old "Psycho" movie. Not that anyone probably remembers.