Join Date: Oct 2005
Location: YYC - soon to be 東京
Programs: AC Prestige, Marriott Silver, Hyatt Gold, Hertz #1 Gold, Radisson Gold Elite, HHonors
Posts: 1,830
You will be picking your bags up once.
Once when you do the BOS-YYZ then you'll see your bag again in NRT when you get off the plane there. You change planes from the Domestic terminal in YVR to the International terminal in YVR and stay airside the whole time.
This is all assuming that you have your itenitary completely on AC.
Sanosuke!