I searched the fare code in Google and found this Japan Travel Agent page:

http://www.tabienet.co.jp/usa-air/6-aa.html

NRT-DFW-DEN for $1,948

NRT-DFW-SEA for $2,031 (16174 miles)

NRT-DFW-ABQ for $2,406

NRT-DFW-LAX for $2,408

NRT-LAX-SAN for $2,414

(sample July 31-Aug 4)

Travel dates: 07/28-08/31

Last date available for NRT-ORD-LGA is departing NRT on Aug 28 according to Google Fights.