The official site of the upcoming game "How to Sing to Open Your Heart" will be opened at Tuesday (2018/9/11), 5pm, Japan Time.
There are twitter icons and also the graph where you can see how far the current progress is now :)
Steam store website is coming soon as well!
And this is the sneak peek of the prologue (Japanese version)
https://www.youtube.com/watch?v=VVfF0wnv91I
Enjoy!