Could the kind folks here point me on the right direction on how to plan for an itinerary? This time I am not looking for a mileage run but more on a last-minute itinerary planning. Skipping the details, I found out this morning that I need to find an itinerary for my wife and I from SFO to Japan. The premise of the travel is that:

June 25: SFO -> CTS (Sapporo) (maybe via NRT?)
June 3: MMB -> ??? -> SFO

I've done some poking around already. It is not hard for the SFO->CTS (or NRT) leg and return. However, there isn't anything that I could find from MMB->CTS (or NRT). Does anyone know how I can go about this?

We'd prefer Star Alliance flights if possible but at this stage, we care about the itinerary and the price more. Please help. Thanks.