I worked while having a lot of exchanges with producer Norihiro Hayashida and director Tetsuro Kodama about the roughly thirty pieces of music spread throughout the film. There’s no “right answer” when it comes to musical direction, so there were places where our visions didn’t quite match, but both of them completely respected my vision, so thankfully, I was able to continue fully writing the music I believed in to the very end. Whenever the footage was improved, for some reason, I felt jealous of its quality, so I mistakenly took it as a challenge to see who could deliver the most, but still, the soundtrack did improve as a result.
Since this film is the epitome of the classic shōnen formula, there’s no real room for experimentation or new points of view. This challenge is a straight ball, and all I need to do is figure out how fast to throw it. Throwing a blazing fastball is definitely too draining for little 52-year-old me, but the sense of accomplishment I felt when I finished writing all the pieces was surely special. That feeling of “well, that certainly made me work up a good sweat” is definitely a good one. But if I ever get the chance to compose for another animated production, I would really like it if it could be a story about a slightly older woman.
— Naoki Satō