romaji と hiragana/katakana and back
Disclaimer
This converter is stupid — it rigidly converts characters, without any knowledge of Japanese grammar or official transcription rules. It misses a lot of the finer points, for instance:
- it doesn't transcribe は as wa when used as a particle (same for を o and へ e).
- it doesn't know whether ō means oo or ou (it always assumes the latter).
- it doesn't care that the long vowel mark ー or constructions like ヒェ aren't officially used in Hiragana.
- probably a lot more.
For a real transcription system, see Hepburn romanization.
If you've found a true bug (read: none of the above kind), let me know — I might just fix it if I can.