791
rule, innit
(ukfli.uk)
Be sure to follow the rule before you head out.
Rule: You must post before you leave.
It's actually from Korean. The Portuguese arrived at least 700 years after the attestation of Japanese "ne".
That's kinda what I was thinking, the Korean use of Neh can be flexible enough to be used as a past particle. The Japanese like to ignore or outright white wash the influence and impact of Korean culture on the island.