[1] pry(main)> k = {'%u9E80'=>'moi'}
=> {"%u9E80"=>"moi"}
[2] pry(main)> pp Hash[k.map{|k,v|[k[2..-1].to_i(16).chr('utf-8'), v]}]
{"麀"=>"moi"}
=> {"麀"=>"moi"}
[3] pry(main)>