Here are stocks that give a flat discount on products with the expectation that you will pay the rest on your own. Does not include gift certificates of specific yen amounts.
Aoki
Aoyama Trading
Asics
Atsugi
DeNA
Dreambed
East Japan Railway
Fast Fitness Japan
Fuji Kyuko
Fujita Kanko
Laxus Technologies
Mitsui O.S.K. Lines
Moonbat
Nippon Parking Development
Nojima
Ricoh
Royal Hotel
Ryohin Keikaku
Sankyo Seiko
Sharp
Takara Tomy
Tokyo Metro
West Japan Railway
World