"Tokusatsu" is short for
"Tokushuu Satsuei" which roughly translates to "
Special Effects Photography".
In recent years however the term has come to be used in Japan to refer to features such as the
Gamera series which trade specifically on their "
SFX". These shows are called
"Tokusatsu" becuase they rely on their effects and little else. There are numerous
old school classics of
Japanese tokusatsu including
Hideaki Anno's personal favourite
Ultraman. If you do enough digging you are sure to find some gems.