yes its just gear box oil. i,ve only ever used car type engine oil in my gear boxes and have never had any trouble. but i do change it every 2-3000 miles. its down to you as to what you want to put in yours.
its a bit like two stroke oil. someone will only use rock and say its the best, some will only use motul etc.
if your that worried go and buy a good make gear box oil from you honda dealer, and ask them if its ok for an nsr.