My Premiere XT was built in the US so there may be different standards from those built in Japan. But:
I did get the factory hitch installed but it only came with a four pin connector, left, right, brake and ground. If you need a seven pin, which includes those pins and 12VDC, brake controller and reverse light, here in North America, you're on your own. The reverse pin on the Gen 5 OB internal connector could be found on connector R79. Apparently, this is not so for a Gen 6 OB. If I do go 7 pin, I will route a 12VDC line and a brake controller line to the back and route a manually switched 12 volt line to use for reverse lights.