How can I mess with the game_system.japanese and data_system.japanese scripts to make it where in the beginning of the game, you can select between english and japanese. If english selected, game_system.japanese would be disabled and the Window_NameInput would load from LATIN1 and LATIN2 and if japanese selected, it would load from JAPAN1, JAPAN2, and JAPAN3.

Here are the code sections if you dont know what I am talking about.
game_system
CODE
  #--------------------------------------------------------------------------
  # * Determine if Japanese Mode
  #--------------------------------------------------------------------------
  def japanese?
    $data_system.japanese
  end

Window_NameInput
CODE
  #--------------------------------------------------------------------------
  # * Character Tables (Latin)
  #--------------------------------------------------------------------------
  LATIN1 = [ 'A','B','C','D','E',  'a','b','c','d','e',
             'F','G','H','I','J',  'f','g','h','i','j',
             'K','L','M','N','O',  'k','l','m','n','o',
             'P','Q','R','S','T',  'p','q','r','s','t',
             'U','V','W','X','Y',  'u','v','w','x','y',
             'Z','[',']','^','_',  'z','{','}','|','~',
             '0','1','2','3','4',  '!','#','$','%','&',
             '5','6','7','8','9',  '(',')','*','+','-',
             '/','=','@','<','>',  ':',';',' ','Page','OK']
  LATIN2 = [ 'Á','‰','Í','“','š',  'á','é','í','ó','ú',
             '€','ˆ','Œ','’','™',  'à','è','“','ò','ù',
             '‚','Š','Ž','”','›',  'â','ê','”','ô','û',
             '„','‹','Ï','–','œ',  'ä','ë','ï','ö','ü',
             '€','’','Ī','Œ','Ū',  'ā','“','ī','ō','ū',
             'ƒ','…','†','‡','Ð',  'ã','å','æ','ç','ð',
             '‘','•','˜','Š','Ŵ',  'ñ','õ','ø','š','ŵ',
             'Ý','Ŷ','Ÿ','Ž','ž',  'ý','ÿ','ŷ','ž','þ',
             'IJ','’','ij','“','Ÿ',  '«','»',' ','Page','OK']
  #--------------------------------------------------------------------------
  # * Character Tables (Japanese)
  #--------------------------------------------------------------------------
  JAPAN1 = [ '‚','„','†','ˆ','Š',  'Œ','Ž','ぐ','’','”',
             '‹','き','く','‘','“',  '–','˜','š','œ','ž',
             '•','—','™','›','そ',  'だ','ぢ','づ','で','ど',
             'Ÿ','ち','つ','て','と',  'ば','び','ぶ','べ','ぼ',
             'な','に','ぬ','ね','の',  'ぱ','ぴ','ぷ','ぺ','ぽ',
             'は','ひ','ふ','へ','ほ',  'ぁ','ƒ','…','‡','‰',
             'ま','み','‚€','‚','‚‚',  'っ','‚ƒ','‚…','‚‡','‚Ž',
             '‚„','‚†','‚ˆ','‚','‚“',  'ƒ','ž','ƒ','＝','˜†',
             '‚‰','‚Š','‚‹','‚Œ','‚',  '‚”','‚’','€€','Page1','OK']
  JAPAN2 = [ '‚','‚','‚','‚','‚',  '‚','‚','‚','‚','‚',
             '‚','‚','‚','‚','‚',  '‚','‚','‚','‚','‚',
             '‚','‚','‚','‚','‚',  'ƒ€','ƒ‚','ƒ…','ƒ‡','ƒ‰',
             '‚','ƒ','ƒ„','ƒ†','ƒˆ',  'ƒ','ƒ“','ƒ–','ƒ™','ƒœ',
             'ƒŠ','ƒ‹','ƒŒ','ƒ','ƒŽ',  'ƒ‘','ƒ”','ƒ—','ƒš','ƒ',
             'ƒ','ƒ’','ƒ•','ƒ˜','ƒ›',  '‚','‚','‚','‚','‚',
             'ƒž','ƒŸ','ƒ','ƒ','ƒ',  'ƒƒ','ƒ','ƒ','ƒ','ƒ',
             'ƒ','ƒ','ƒ','ƒ','ƒ',  'ƒ','ž','ƒ','＝','˜†',
             'ƒ','ƒ','ƒ','ƒ','ƒ',  'ƒ','ƒ','€€','Page','OK']
  JAPAN3 = [ 'Ａ','Ｂ','Ｃ','Ｄ','Ｅ',  'ａ','‚','ƒ','„','…',
             'Ｆ','Ｇ','Ｈ','Ｉ','Ｊ',  '†','‡','ˆ','‰','Š',
             'Ｋ','Ｌ','Ｍ','Ｎ','Ｏ',  '‹','Œ','ｍ','Ž','ｏ',
             'Ｐ','Ｑ','Ｒ','Ｓ','Ｔ',  'ｐ','‘','’','“','”',
             'Ｕ','Ｖ','Ｗ','Ｘ','Ｙ',  '•','–','—','˜','™',
             'Ｚ','［','］','＾','＿',  'š','›','｝','œ','ž',
             '０','‘','’','“','”',  '！','ƒ','„','…','†',
             '•','–','—','˜','™',  'ˆ','‰','Š','‹','－',
             '／','＝','＠','œ','ž',  'š','›','€€','Page','OK']
  #--------------------------------------------------------------------------
  # * Object Initialization
  #--------------------------------------------------------------------------
  def initialize(edit_window)
    super(edit_window.x, edit_window.y + edit_window.height + 8,
          edit_window.width, fitting_height(9))
    @edit_window = edit_window
    @page = 0
    @index = 0
    refresh
    update_cursor
    activate
  end
  #--------------------------------------------------------------------------
  # * Get Text Table
  #--------------------------------------------------------------------------
  def table
    return [JAPAN1, JAPAN2, JAPAN3] if $game_system.japanese?
    return [LATIN1, LATIN2]
  end


Is there any way to do this? Like define a game_system english and put this line in on name input?
return [LATIN1, LATIN2] if $game_system.english?

EDIT: Please bear with me, I have no knowledge on RGSS3. :/
EDIT2: Also, how do I set the game systems default language to english, because in game, its japanese, and if I don't remove a line of code in window_nameinput, it's in japanese. Also, in battle, enemy's name would appear as Slime[], Slime[], Slime[] instead of Slime A, Slime B, Slime C.
Where is the line of code to fix that.