Japanese phonemes (was Re: The Monovocalic PIE Myth (wasGermans have no /w/, ...))

Roger Mills wrote:
> Eh?? Ryukyu islands; Ryoanji temple (with the famous sand garden); Roppongi
> (sp.?) a district in Tokyo IIRC. Rashomon the film. Ran ('Chaos') another
> film, Japanese take on King Lear. Not to mention everybody's favorite
> _ramen_ ???
*Native* roots, I said.  These examples all use Sino-Japanese roots.  I
first noticed this when I was looking for something in a Kanji
dictionary, under the on/kun index, and noticed that all the r-row
entries were in katakana (indicating Sino-Japanese as opposed to
native).  This was later confirmed in _Languages of Japan_.

Incidentally, Korean has a similar restriction, except it extends to
Sino-Japanese roots as well.  There, underlying /r/ is realized
word-initially as null before /i/ or /j/, and /n/ elsewhere (but
reappears in compound words).