Use of 3 phone in Japan

Can we use 3g cell phones in Japan. I have a LG U8330 and my wife has a LG KF310. Does anyone know if this phone work in Japan? Also what are charges.

It depends on who your domestic carrier is.

Also check out the costs. I asked my carrier (Sprint in the US) and they told me it would cost $2 a minute. You can rent or get a pre-paid phone but I am just going to do without while in Japan this summer.

phones need to have 2100mhz band to work in japan, not just 3G. Roaming is ridiculously expensive: we relied on prepaid phone away cards from home, and rang from the hotel if necessary. As we took a laptop we also used Skype a lot as hotels had free access. Family were told to ring/sms mobiles only in emergencies.