I don't really get why Sony don't just fund the translation, maybe even handle the manufacturing side etc, and give Namco a "free" game to release. Namco can't have an issue if they don't have to pay for the release and translation costs will surely be nowhere near what the costs would be to make a brand new game.
Sony would still get the royalties from western sales that they usually receive from 3rd party releases, Namco have no reason to say no, Vita gets new games which could help drive hardware sales. It would certainly cost less than they paid to make Activision a dire Call of Duty game which most likely put people off the Vita once they'd got it.