Transfer from int to dom in Haneda

Hello everybody!
My final destination is Sapporo Chitose so I bought a flight ticket from Rome to Sapporo with Lufthansa. I will arrive in Tokyo Haneda at 6.55 a.m. from Frankfurt with a ANA flight and the flight to Sapporo will be at 8.15 a.m. with a AIRDO flight so I have to move from International Terminal to Domestic Terminal 2. I am very afraid to lose flight for Sapporo but this was only opportunity to arrive in Sapporo without spending a lot of money. I read about "direct buses for checked-through passengers between the secure areas of the international and their respective domestic terminals to further reduce transit times.". Does someone know something about these direct buses? Where do I take this bus?
Thank you so much in advance

The information you are looking for is here: http://www.ana.co.jp/wws/japan/e/asw_common/departure/airport/map.html...

Hmm, however since your domestic flight is operated by Air Do, it is possible that you don't qualify for this service, the page is not very clear about that. You can contact ANA to ask them. http://www.ana.co.jp/wws/japan/e/local/site-help/share/contact/#anchor...

I asked them and this is the answer:

If you book a flight reservation for ANA international flights, minimum
connecting time from ANA international flights to ANA (AIR DO) domestic
flights at Tokyo(Haneda) airport is 80 minutes. You have just 80 minutes
for transfer about this itinerary.

For more information about transfer, please see the following URL.

��Transit Information
http://www.ana.co.jp/wws/japan/e/local/domestic/prepare/checkin/transi...

If your flight for international flights is other airlines, minimum connecting
time is longer than ANA. It depends on the airlines which you take, so
please inform us your reservation detail.

I don't think it's an useful information :)
I would like to stress that I bought an unique ticket with Lufthansa, from Rome to Sapporo.

They were more helpful when I asked them about my baggage allowance a couple days ago... Did you give them your reservation number (six characters)? Since they seemed to not know about your itinerary, it seems you didn't.

I gave them my itinerary but that was the answer. I found an interesting video on YouTube:

https://www.youtube.com/watch?v=QY3c-EGOFmI

The question is: I will arrive with ANA in Tokyo but I will departure with AIRDO (a partner company anyway), can I take that transfer bus? I asked to ANA but still no answer.