While using Rails console, when I input ä, \\U+FFC3\\U+FFA4 appears. Of course I can input Unicode characters outside of rails.
ä
\\U+FFC3\\U+FFA4
I\'m using
Most likely you've got readline issue, try to re-install Ruby with readline support. https://github.com/wayneeseguin/rvm/issues/1016 or http://blog.rlmflores.me/blog/2012/04/25/adding-utf-8-support-to-rubies-compiled-through-ruby-build/