It was domestic. This trip wasn't the one I'd mentioned earlier in another thread; it was HIJ-HND(overnight)NRT-YVR. I didn't notice because unlike most tourists, I have Mobile Suica on my phone, and that was how I paid for pretty much everything between HND and my hotel- train fare, snacks, drinks, some shopping, and when my balance ran low I just tapped the "quick reload" button and it pulled funds from the card I'd linked before.

Having Mobile Suica made it too easy, else I'd have noticed my missing wallet much earlier, like when I tried to board the train leaving HND (I keep all cards in my wallet, so I would've noticed then) or at Shinagawa, where my Suica ran low, because you need cash to reload a regular Suica, and all my cash was in my wallet.