From御(o,honorific prefix) +前(mae,“front”), literally "honourable presence in front of me". Originally a polite pronoun applied to highly respected persons such as emperors or gods.[1][2]
Ore wa kebiishi no chō no yakunin nado de wa nai. Imashigata kono mon no shita o tōrikakatta tabi no mono da. Dakaraomae ni nawa o kakete, dō shiyō to iu yō na koto wa nai.
I am not an official of law enforcement, but simply a traveller who's happened to come across this gate a few moments ago. I'm not here to bindyou in ropes or any nonsense of the sort.
Slightly condescending if used by a higher status peer to refer to a lower status peer, very informal between close equal-status peers; (very) impolite in other situations.
In many Japanese dialects, it is rather the standard 2nd-person pronoun, equivalent in usage to standard Japaneseあなた(anata).