i doubt you'll make it. even if you run..and they close the doors to the flight at least 10 minutes before if not more. and don't forget that you have to go through a security check at NRT which includes xrays and all that good stuff.

how were you even able to book this Itinerary?

These your flights?
All Nippon Airways Flight NH5 on a Boeing 777 (jet) in coach class
Departs Los Angeles, CA (LAX) 11:35a 11 hrs 50 min
Arrives Tokyo, Japan (NRT) 4:25pm

NH933
Departs Tokyo, Japan (NRT) 5:10p
Arrives Guangzhou, China (CAN) 9:35p

ok..after looking at that you might make it but it's going to be close. You have about 45 min. 5 min to taxi the plane..another 5 to deboard maybe 10-15 to get through security and to your gate.?? but of course you have a two year old so that might factor in.