For a limited time you can save 15,000 miles to get to or from Narita, Japan. Redeem 45,000 Mileage Plus miles for roundtrip travel in United economy from Washington, Dulles. Travel is valid through Mar. 31, 2007. Your award can start from other cities but must be routed through Dulles and must be on United, not other codeshare partners. Essentially this is a 25 percent discount since the normal award is 60,000 miles.