Congratulations on your first release - and with such a masterfully assembled visual novel! I was immediately impressed with the PC-98 + 90s' retro anime look, on both the characters and the rest of the visuals. It shows a lot of personality - down to things as subtle as the static-ey effect on the splash screen.
Of course, the writing itself does a lot for the theme and more! The main theme with Miko & Saki got a lot of love put into its writing. The calm music does excellent work to accent the story. I can tell that a lot of good research also went into the many other details in the story.
Overall, this was an excellent use of theme - and excellent execution all around. This is easily a favorite of mine, so thank you for making this visual novel!