+ As already mentioned, there's a bug (よ should be "yo", tool says "re")
+ I think it would be good to allow alternative transliterations. E.g., "tu" for つ, "si" for し, "ti" for ち, etc.
+ It would be good to support composite/modified characters as well, stuff like しょ ("sho"), ちゅ ("chu"), じ ("ji"), じゅ ("ju"), が ("ga"), ぱ ("pa"), etc, etc, etc.