引 き篭り Hikikomori ひきこもり (Trivial Math-Rock band from Sicily)
if you don't have other things to do, write to: hikikomoriband (at) altervista.org - for more info.
one on top_left one on top_right
  one on bottom_left one on bottom_right

Hikikomori 2006 - all rights paranoidly considered