Covenants
Althought Covenants hasn't been released yet, the shop managed to produce an order list for it. They took my name and phone number, and promised to phone when it arrives... which they humbly suggested could take as long as two to six months, given a February 3rd shipping date.
Still, I'm sure they are just being cautious. Well, I say sure...
Getting there
I forgot to take the instructions, and so put on my best big-happy-gaikokujin smile, and wandered into the local koban (Shinjuku station police box). They were terribly helpful, though once they realised that they were helping me get to a games shop, as opposed to a hobby shop, the police lost most of their enthusiasm.
They provided me with a map with A -> B marked, though I had to help them find where the address lay on the half-page of 'Yellow'-something shops in their shop directory.

Oishii Goodness
I made this list of what the shop had on the shelves for some Ars players in Chiba, but they've already ordered...
4th Ed. AG#:273,272,271,270,269,266,265,263,262,261,257,255,254,252,0204, The Bishop's Staff, Return of the Stormrider.
5th Ed.
AG#:02077, 0276x2
Rune Core, plus 2 supplements
2 Feng shui supplements