The NRT hub is timed and operated for connecting traffic. Arguments like "I got lost in the airport" are unlikely to hold much weight, as (eg) there is staff on hand to direct you exactly where you need to go. If you're going to do this, be prepared to pay for a new ticket, though as usual YMMV according to the agent you get.

That said, I'm surprised you can't get a stopover. Pretty much every ticket (revenue and award) transiting NRT I've booked allowed for a stopover in Tokyo, and I've taken advantage of this several times. Also, if you're flying out of LAX, try LAX-HND/NRT-PVG. That should require an overnight.