The game can be opened in "edit" mode by using Rpg tsukuru 2003 (or Rpg maker 2003).
Text is stored within events (that are either a sprite or pink squares on the map), and these can be edited easily. The thing is: This is legit a massive amount of text, That would take quite a while to be finished. And there is a catch: Some events are repeated in certain maps. Like, sometimes the player can walk up, left or right, so the same event to trigger dialogue may be repeated 3 times. Probably just editing one event and copy-pasting it in place where the other two are could work.
I imagine that the most practical process for finding and fixing typos would be like:
- playing the game until a typo is found > going back to the editor and finding the map where the event with that specific text is > fixing it and play-testing to see if nothing is broken.
Seems simple enough, but i have to emphasize that it is a time consuming task. For being a cell-phone game, this has so much more text that one would expect.