During the first Tea club quest, where you are putting away supplies with Koko and Kokoro, there is a game lock that I am unsure how exactly to get around.
During the point where you choose whether or not to stay with Koko or return to your dorm, if you choose to stay with Koko, after the CG where Koko is sleeping on your shoulder, the game freaks out. It plays the dialogue for the entire scene again, including the first choice where you either lean in for a kiss or continue working, and then when Koko says "I'm done!" and would begin walking towards you the game just locks.
Choosing to just return to the dorm works fine, but obviously, it locks you out of content. Choosing to stay with Koko locks your game regardless of what option you choose for the previous choice, it doesn't matter what order you get the supplies in, and it doesn't matter what time you choose to do the quest. I tried reloading multiple previous saves and replaying until that point and it still locked for me.