I think this is different than 108835, about non ascii and irb window;
this is just running a ruby file via file menu, such file has a line
puts "string with multibyte characters" - the characters show as random
ascii in the output window, even though the project encoding is utf-8.

am running in ja locale (not ja utf-8 locale on solaris)

when change encoding of a ruby project to euc-jp (am on solaris) and have a
new ruby file, running that file does show the multibyte ok in output window.

using irb to puts the string with multibyte is ok in utf-8 project encoding
or when change to euc-jp encoding but need to see if its ok with new project
in euc encoding but thats for 108835.