There are 3 routes, maybe that's what you're missing? You choose them during certain points in the story when you have option for "difficulty stars" and saving. I think some events might also be tied to level of your character or only triggerable at certain times. I'm not sure about this tho.
i've noticed something with the "Note from Receptionist 2" i have tried to talk to the accessory mina a few times but for some reason my character hasn't gave it to her, possible bug?