how to make unicode 6 chars show in emacs?

[Xah Lee]

Unicode 6 is now supported in emacs 24. For example, call ucs-insert
【Ctrl+x 8 Enter】 then “GRINNING CAT FACE WITH SMILING EYES”, then you
get this char 😸.

however, emacs doesn't show the char unless you explicitly switch to a
font (Symbola) that contains the char. But the grinning cat shows in
browsers.

is there anything one can do for this?

does emacs rely on OS's font substitution tech or does it has its own?

( link to Symbola font http://xahlee.org/comp/unicode_6_emoticons.html
)

 Xah