I think I've found out one of the causes of the game doing a black screen for some (or maybe a lot) of you who are trying to play our games and I'll be updating Ramen no Oujisama and Summer in Springtime builds later to address this. This has been around for quite some time already and I've gotten feedback about this since several months back. Wasn't quite sure what it was until now. The game affects the online versions of the build and if you are on a slow connection with the website (or the website is slow). The game tries to load ahead without the main stuff loaded up first, causing the black screen. This time around, the game will check if the game's ready to be initialized before attempting to start.
Thanks to mz87 for the bug lead!