I meet up with a few managers and traders at my bank in Tokyo last time I was there. One of them said that during 2006 we had hired 10 people from the Boston career fair and that during 2007 we planed to hire between 40-50 people at the fair! She would personally go there to interview people.
She also said that for some positions they preferred gaijins or at least Japanese that had studied their entire degrees in english speaking countries. According to hear most of the students from universities like Keio or Waseda didn't have good enough english to get by in the BIU at most big US I-banks.
She said that this differed from bank to bank somewhat, Bear Stearns and Deutsche Bank where much more local in their business culture than some of the others for banks an example.