Wieso ist es nicht Hepburn?
http://en.wikipedia.org/wiki/Hepburn_romanization wrote:
In revised Hepburn:
When he へ is used as a particle it is written e.
When ha は is used as a particle it is written wa.
When wo を is used as a particle it is written o.
The long vowels are indicated by a circumflex or a macron—e.g., long o is written ô or ō.