Upvote:1
Based on your question, it seems these are separate bookings.
Per TIMATIC, the database used by airlines:
Visa required, except for Passengers with a passport and a confirmed onward ticket to a third country within 72 hours can obtain a Shore Pass on arrival if there are no connecting flights on the same calendar day
For logical reasons, I suspect this information is incomplete and that your scenario would qualify for this visa exemption. Nevertheless, based on the above you're not getting on the flight to NRT without a visa with separate bookings (even if not checking a bag, the problem is you won't be considered a transit passenger).
So yes, you'll need a transit visa with separate bookings. If it's a single booking, then any bags will be checked through, and you won't need a visa.