im in japan and my phone say no service

Hmmm... Are you sure your device is a global device? 

Do you have international roaming enabled on your line? That is not the same as the international passport plan. It is a $0 cost feature that must be enabled or your phone won't get service. 

i do have it to but it still says no service 

I could be wrong but your issue may be incompatible networks. From what I can tell, the Japanese carriers operate CDMA networks, not GSM. You may only get service when in an area that also has LTE service. 

My son and ex husband just returned from Japan and had no problem with service with the passport plan.  In most places there was free wifi without a sign in required.  They only need cellular when they made calls or used text.

Japan did use CDMA 10 years ago, but doesn't use CDMA for 3G now, they have UTMS and LTE.  No 2G 

What @sandblaster is suggesting is you didn't add the pay per use to the line in addition to the passport plan.  See the bottom right photo taken from the online account.  

You can also go into network and try a different cellular network to see for that helps