What is Oro? I've asked myself that very same question so many times.
Is it a fish? No..
Is it a person? No. But it is something we all should know.
I know your probably asking yourself right now.."Oro? What the heck!?" Well, if you know what oro is you may now pat yourself on the back. If you don't you might want to read on.

Or*o (Or'ro) Interjective - 1 : And exclamation of surprise or confusion 2; The word uttered often by Himura Kenshin when he is confused and surprised.

Oro is a real word too! In Spanish Oro means "gold".

Not only Kenshin used this word but also Sanosuke as well. Not only that, oro was also used in other animes as well. Excel from "Excel Saga" used it in the second episode when she thought her bike was stolen.

The neat thing about this word is that you could be creative and extend the word. You could add an "ro" to the end to make "Ororo" or you could extend the O's to make it "Oroo", or even "Ororoororo".