What I did for mine is just put this at the very beginning of my introduction event. It requires 3 small call scripts, but they have to be seperate.
Script: Font.default_name = 'Arial'
Script: $scene = Scene_Map.new
Script: Font.default_size = 21
I just made the font a bit smaller, remember that you can't include downloaded fonts in your Defaultus game so use ones that come standard if you do wanna change.
Good luck with your game :D.