Well, I have doubts that japanese people will really want to play, speculating on Bitcoin.
We have a big handicap here (I live in Tokyo) : MtGox. Everybody think that MtGox = Bitcoin so Bitcoin = dangerous.
Japanese people love new technologies, but without a very heavy "back up" from a very big Japanese company, Bitcoin will have a hard time being trusted. I hope Rakuten will change that !
I don't think exchanges in here has 0 fees on transactions.
I'll try Kraken later, but for the moment the BTC/JPY pair has 0￥ volume. Even if I was really disappointed on Kraken decision to delete the DOGE/EUR pair which had ~1500$/day volume.