I still find that odd. One would think that States would have at least similar requirements, and thus allow the licenses to be transferrable.
Gosu is pretty awesome, if you're okay with absolutely crazy martial arts with
Qi and everything. Keep in mind that if/when you hit Season II, the writer did another series named Yongbi that, for my money, isn't nearly as good (it has its good points, but is really waaaay too caught-up in somewhat immature humor) but DOES have links with Gosu. Some of the characters transfer over, though they're much older.
Good news is that you really don't have to read Yongbi to at least follow what's going on (if you don't enjoy Yongbi, don't try to push through it just to get the background - it should have been called LONGbi).
Watch for the little comments some of the characters drop about fighting, martial arts, and that kind of thing. Hidden gems, really.