What is the "-shi" ending's meaning?
"-desushi" mean "becase" and "and".

Let's take a look at a few quotes from episode 5 for example.


  ふぉぉぉ！燃える展開です!!
  ちよりはバーニングチョリソーですしー!!


Wow! This is a burning development!! Because Chiyori is Burning Chorizo!!


  るぅ子さんがやらないなら私がやります
  ちよりがやりたいですしー！


If Ruuko doesn't play, I'll play.
Because Chiyori want to play!

The word "-desushi" itself is normal Japanese.
But the overusing "-desushi" is part of slang of young people.

In this anime, "-desushi" is used for accent of character like "-nyo".