Because freedom, Christianity, Jews and Shia are their main enemy.
And they want to bring the caliphate to the whole world, well why Europe and USA target?
Because according to them these countries have given a lot of freedom to their people and interfering as well with the middle eastern concerns.
Well wait for the day when China and Japan will attack ISIS they will revert.
Well if you look at Chinese Uyghur Muslims, they are controlled very harshly by Chinese government. So it's a bit challenging to plan some big attacks in China. As there are very little Muslim population in Japan the same goes here too. As far as India is concerned, I can't say none, but a negligible fraction of Muslims support ISIS.