XO means
Badtz Maru in
Japanese.
X means
wrong, and
is often accompanied by a
buzzing sound, even in
conversation.
O means
right and is accompanied by a
doorbell sort of sound, which is pronounced "
pin-pon!"
when people say it.
XO is also the symbol for famous children's cartoon
crow
Bad Badtz Maru, who is one of
Hello Kitty's friends.