Buses to Narita Airport

Maebashi/Shibukawa/Takasaki/Fujioka/Isesaki (Azalea Bus)
http://www.kan-etsu.net/azalea/top.htm

Ota/Oizumi/Tatebayashi (Maple)
http://www.chibakotsu.co.jp/kousoku/maple.htm

Kiryu\Ashikaga\Sano (Salvia)
http://www.chibakotsu.co.jp/kousoku/salvia.htm

Kimousine Bus(Isesaki)
http://www.limousinebus.co.jp/

For information on the Seishun 18 Ticket see here:
http://www.gunmajet.net/node/920