Fosters is crap, and I say this as a trained bartender. Most export beer from most countries is pretty bad.

As far as immersion goes, it's less about how much you like a place than about how much you get into it. For me I fond if I go out on nights before work then I don't do so well at my job the next day, so I try to focus on work first and play/immersion second.
I've got five years here, I'll be plenty immersed and more so as my Japanese improves. Right now I'm one of those recently arrived foreigners, and one whose job is largely pandering to those English speaking Japanese.
On which topic I have to go now and see one in particular...gomen.