Congrats on the game! I like your idea! (it’s somewhat similar to mine xD), and you have a fun art style.
As mentioned before, it seems that after a while the letters start going behind the quest posters and, more importantly, they are too small, and the text is hard to read when it’s outside the letter.
Edit: Also, after the required quests are complete, on the report screen, the shop and the arrow cover most of the text there