Well, I have no idea what AxKit is, but if you are feeding the data to it it should tell you what encoding it wants. utf8::encode() would be one way to force utf8-encoding, yes, but if you are sending the data via a filehandle, applying a utf8 layer to the filehandle would be better.
However, if AxKit is a perl module whose functions you are calling and passing data, it
take your \xa5 whether it is utf8 encoded or not.