Okay, I remember downloading this from somewhere else and having the same stuck problem and I have a "solution" that will skip part of the story but it's better than nothing. It'll require a little of understanding of how Unity load levels.
Go to AnaSyoujo_Data folder and look for the files named "level<number>", those aren't the "levels" per see as they are the scenes, with 0 being the splash screen, 1 being the menu and 2 being the troublesome hole scene.
Rename "level2" to "level2_og", then make a copy of "level3" and rename it to "level2", what you'll be doing is essentially replacing the broken scene with the next one.
It'll skip the hole scene (ironically) and will throw you directly at the class room, from there on it should progress smoothly and once you're done you'll get the free mode. After that you can replace the faux "level2" with the original "level2_og".