And how can you know is console is using utf-8? Could be Windows and CP850
I would't claim I know. But since length 'Kü' is 3 but displays as 'Kü', I just guessed that a multibyte encoding is in place. CP850 is a 1-byte-encoding and should behave differently.
As for Devel::Peek: Those commands will show me the hex codes in ASCII
Devel::Peek will also issue several lines of data which are totally useless unless you're debugging XS code or Perl itself. A decent print unpack 'H*',$data does the same with less fuss.