For those not familiar with ATM transactions in Japan, be aware of the need to find an "ATM for foreigners" as described above.
I don't think they are specifically marked "ATM for foreigners" on them (maybe on the map provided to one of the posters), I don't recall actually seeing it on the Citibank machine. What you want to look for is either citibank, or somthing affiliated with the Japan Post network (look for the Japan Post type logo) as shown by LapLap.