Best place to buy yen in Tokyo?

I'm arriving in Tokyo next week from China. I will be working as an ALT in Tochigi. I am on a tight budget until my first pay and so don't want to be ripped off when exchanging my Chinese Yuan for Japanese Yen. Where is the best place in Tokyo to buy JPY? Are the exchange booths at the airport fair? (I've noticed they are rip offs in other countries). I'm exchanging 11500 Chinese Yuan and I need at least 190000 JPY or I'll have to get an advance to make it to pay day.

I'm from canada and I find atm/visa machine to be the best, exchange rate is 2.5% plus $5 fee. Currency exchanges can charge 4%+ and tell you their rates are low.

isn't the best exchange rate getting it from china, I can't confirm this, but getting yen from hong kong is pretty good, although the yen has gone bad in recent months against the hong kong dollar.