For an international itinerary, you can spend up to 24 hours on the ground and it still counts as a layover. I'm not sure if the extra distance (TYO-ORD-LAX is 47% farther than flying direct) will be a problem though. Booking the connection you want (as opposed to the shortest time on the ground) generally requires using the Multiple Destinations option in the flight search, but even so it often fails for itineraries you really can book if you call. I wasn't able to find a pair of dates where this search worked, despite apparent availability segment-by-segment. My suggestion would be to find the two segments you want using separate one-way searches and then see if you can get a phone agent to book them as one award.