Some says we need up to 60k chars for Japanese.   However, I must say
I don't know such huge number of Kanji which eceeds my memory capacity.
Most of 64k chars may be in very limited use such in some ancient documents
etc.  :-)  If "computer" must deal with all of those documents, yes, we may have
to have 64k chars...

The 16 bit limits will meet problem, in practical, to write person's name, some
of which are named using wrong Kanji when all Japanese were permitted
to have their own family name about 150 years ago.  ^_^  Now, we cannot say
it's wrong anymore. :-)

Sorry, this is off topic.

Kenji