Finished all the Prologues so I can choose mode and difficulty, etc. The Secrets section says you can unlock entries by completing story events, by winning them in battle, or by paying mystery points or whatever—if the list shows a mystery point cost to unlock something, you HAVE to pay to unlock that, right? I didn’t want to pay for something I could unlock just by playing the game, but the big numeric gaps between listed entries makes me think this isn’t a danger.