Another one who created an account on itch.io just to leave a comment ...
You have no idea how long I've been searching for some good interactive fiction with a story that occupies the rare middle ground between banal left-to-right conversations in anime cliche and overwrought essays of pretentious purple prose. This demo sucked me in immediately and whenever there's a full release I'll be buying it on day one.
Your English is outstanding and I didn't suspect it wasn't your first language until I was halfway through the demo (a few preposition choices here and there - nothing major and nothing that detracted whatsoever from my enjoyment).
It's a rare talent in any language to have a feel for real environments and real people, for showing rather than telling, and trusting an audience to draw conclusions without spelling them out. I hope your game receives all the success it deserves when it's released - good luck.