Might have something to do with those phones using a part of the spectrum (in the US regulated by the FCC) that is not available in Japan (and might disrupt other services).

I figure it's probably something like that. By the way, this Sunday in Misawa is the biggest day of the year... Burger King Day! (Also known as the Misawa Airshow).
Here are the details: http://www.misawajapan.com/festivals/airshow/airshow.htm

Haha, sweet

Good thing I left my phone back in the states... The last thing I need are more bills to pay around the house.

I was stationed at the Marine Corps Air Station in Iwakuni and they told us that we also could not use cordless phones even in our rooms. Some of us believed the idea was that cordless phone transmissions were easier to intercept. This was a real danger because we had some arabic folks with shops right outside the main gate that we were suspicious of. Anybody could peace together bits of info from seemingly harmless calls home (deployment schedules, air shows, etc.) I don't know about a $10,000 fine for cordless use though.

Here is the full scoop on what is and is not illegal here in Japan: http://www.cfas.navy.mil/soundingsonline/Contents/news/Wireless_Interference.htm

Well, since that url is not being displayed correctly, I'll paste the important stuff here:

The following is a list of prohibited frequencies:
-49 MHz (awaiting guidance from CNFJ frequency manager)
-900 MHz (strictly prohibited)
-2.4 GHz (10 mW power limitation)