We've released a small quality of life update that includes a full walkthrough of the romantic routes for anyone who finds themselves stuck. This is a major story spoiler so consider yourselves warned.
You can find the PDF walkthrough in the drop-down menu at the top right, choose "My Library" and "Download" under Glass Hearts.

Another important improvement makes Subin's route just a bit easier to achieve.

There have been a few text changes and minor fixes that improve the overall experience.

Let us know if you're having any issues with the game.