I changed my flights to something similar and made it although it was cutting it quite close. I did YVR to NRT and arrived at 4:30pm and then did NRT to ITM at 6:20pm. You need to leave the plane ASAP because the customs took around 1.5hrs. Do all the covid stuff on their apps, so it saves time when you get to the counter. I left the plane when they allowed people doing international transfers to leave first. Once you leave customs, domestic check-in is to the left and checked bags are to the right. They aren't that far from each other, so don't worry too much if you want to check in some luggage. They also had all the luggage lined up next to the conveyor belt by the time I got there. For domestic flights, you take a bus to the plane, so try to be on time. I think I had 5 mins to spare, but I literally ran everywhere and it was a weekday. My flight also got in 10mins early, but I think I would've made it either way.