Hello! Of course I read you, don't worry at all!
I'm afraid I've tested the game and, at first glance, everything works fine for you. You mean the part where Usagi teaches the player how to fight monsters, right? It works for me. Could you tell me at what exact moment the game crashes for you? If you play that part again, does it crash again? Have you done anything special, anything that could cause the bug? Anything other than strictly following the main quest. It's not to blame you, of course not, it's to look for possible external factors that generate the bug.