The exact spelling for Japanese is a lot more reasonable, though. In English there are lots of spellings for the same pronunciation. In Japanese there is only one spelling for each pronunciation. If you get it wrong, then you are writing a different word and there is very little you can do in the general case.

Of course the problem with romaji is our habit of spelling things wrong :-) To highlight the irony, "romaji" in Japanese is ローマ字 (literally roman (Roma) characters (Ji)). The ロ is "ro", the マ is "ma" and the 字 is "ji". But there is one character left! ー extends the "o" sound for the "ro" for one extra "beat" (Japanese is a rhythmical language). I don't even know the correct transliteration for this other than "rōmaji". For Wāpuro rōmaji I think I would enter "roumaji", but I think this is not actually correct romanisation.

Even to this day I mispronounce that word because of stupid romaji :-)