You have to read a condition of carriage of ANA ticket. I am not familiar with ANA’s condition of carriage, but for AA change of aircraft is enough reason for refund without penalty. I quickly glanced a condition of carriage of ANA and could not find change of aircraft listed. You have to read it carefully,

Condition of Carriage

From my experience, North America reservation center hire local people with English as native language. If you choose English as option then likely there will be very minimal to no language barrier. One thing to remember is that Japanese way is strictly by the rule.