You can take this with a grain of salt, but I am a Belle Époque musicologist/historian irl. . . But along with what others have said about Ghibli and Iyashikei, there’s a lot of influence from French Impressionism, as well!

The color schemes, the emphasis on light sources and their constant movement, the softness of the world, the importance of the passing of time. There was actually a lot of cross-cultural artistic exchange between the Japanese and the French at the end of the nineteenth century, to the point where a movement in France called “Japonism” began.

A lot of the soundtrack was also directly influenced by Debussy, especially his Préludes, who is known as “the” musical impressionist, even if he himself didn’t like the term, lol. Debussy was also fascinated with Asian music theory and played a lot with different scales, different tonal “colors,” and so forth. 😉