Air Canada has round-trip flights from New York/Newark (EWR/LGA) to Tokyo (NRT) for $778-$783 with a connection. Flights in April. Departures on Monday, Tuesday, Wednesday, and Sunday.
It’s rare to see April round-trips to Tokyo in this price range on a major airline. Last time this happened was November 2024 (link).
You may be able to fly for cheaper ($508 r/t) on Air Premia, but you’ll be adding 13-hours of transit time (5 to 8-hours each way!) to your trip. I don’t think the savings are worth the pain, but it’s up to you.

