I wasn't sure exactly where to post this question since it may fall into either film or history so I'll try here first. I've recently been re-reading some Usagi Yojimbo by Stan Sakai and that got me in the mood to watch a few few Toshiro Mifune films, in particular Yojimbo and Sanjuro. I've noticed in all three Toshiro and Usagi both say something that sounds familiar to Obaiyo. And it's even written that way in Usagi. The translation is usually put as See Ya or See You Later.
I've tried looking this up but get all the usual phrases...I was wondering, since Mifune was a fan of using older language and Sakai had an eye for history, is it an archaic way to say See You Later? Anyone hear of this or see it? Because it's driving me crazy!