Just because it is made by a reputable company in Japan doesnt mean it meets the regs for CAMS here, look at compliance. Why do cars have to be complied?
Cars out of the UK and Japan are amongst the safest in the world yet as imports, they still have to be changed to meet ADR's, same goes for stuff that might meet Japanese competition equipment regs, doesnt automatically mean it meets CAMS legislation.
It isnt about who goes fastest, who has the more dangerous sport, it is regulations.