Meaning of おん after a name


I was talking with a Japanese girl by message and she asked me how to read my
name, which is Andrea (Spanish female name). I told her it's アンドレア but that
some friends call me あんちゃん because it's shorter.

Her answer was: あんちゃんおん

I didn't understand the meaning of this おん and after searching in dictionaries
and so on I have no clue of how to interpret this as something you would add
to a name.

Thank you in advance.




I never heard this before, but if she is an idol perhaps it is some sort of
"cute" sound she adds at the end? I hope someone else has the answer. It is
very interesting.

