I limp.

We expect the nitty asian lady to fold a lot regardless of whether we limp or raise.

Our pot odds are fantastic and from what you said I gather that the BTN is reasonably passive and isn't going to be raising it up very often.

The reason I dislike a raise is because BB is unknown so we don't know how he reacts to raises and he will be getting decent pot odds to continue because the button won't be folding to a raise and MP also isn't likely to fold even if BTN & BB fold. There is also the chance that MP is tilting so if we raise and BTN & BB fold he could very well 4bet us with a very large part of his range and I don't like playing 45s HU when we don't really have any fold equity and are more likely to be behind his bluffs.