I stumbled on this by chance and it’s a very neat project. There are definitely some areas where it could be improved, like saving and loading game states, importing dialogue for custom characters, or other options for window size. Regardless, it’s a very interesting demo.
Do you plan on adding more content in the future, or are you simply releasing the game as-is? I see that the project files are on GitHub, but there’s no license on the page, so even if I played around with the code I’m not sure if it would be okay to share a modified version of the game.
Anyways, thanks for creating this, and best of luck in your future endeavors regardless. I hope this comment translates into Japanese well enough that you can understand it!