No.  To roam in Japan, you need either a CDMA phone with the Japanese
frequencies (none of the US carriers sell a phone with those frequencies,
but some foreign carriers do) to roam on KDDI, or a UMTS (a.k.a. WCDMA)
phone with the 2100 band (European 3G phones do this) to roam on Softbank.

GSM phones, or North American CDMA phones, will NOT roam in Japan.

The ONLY Verizon device that works in Japan is a data card that has UMTS.

If you have GSM service (T-Mobile or AT&T), you can rent a UMTS cell phone
from Softbank at the airport and use your SIM card in it.  Alternatively,
buy an unlocked UMTS cell phone from eBay.

HOWEVER, given the EXHORBITANT cost of international roaming, I recommend
that you just rent Japanese service (with a Japanese number) at the
airport.  The real cost of this is renting the phone; if you buy a UMTS
cell phone (either unlocked, or locked to Softbank) from eBay, you can
rent a Japanese USIM card for 105 yen/day (less than $1/day) plus call
costs.

-- Mark --

http://panda.com/mrc
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.

For a price, Verizon will send you a phone on a day-by-day rental for
foreign travel.  It is on the website.

I doubt that the rental is a Blackberry.