Keyword parameters are introduced from Ruby 2.0. This feature helps us to write readable Ruby program. However, Ruby 2.0 and Ruby 2.1 have a performance issue because the keyword arguments are passed by Hash objects. Ruby 2.2 solves this performance issue and achieves over 10 times faster implementation. In this presentation, I introduce a brief history of Ruby's keyword arguments and keyword parameters, and implementation techniques to make them faster.