Seiko is one of the three main companies of the `` Seiko Group '' which are the Seiko Holdings Corporation ( Seiko ) , Seiko Instruments Inc. ( SII ) and the Seiko Epson Corporation ( Epson ) . The Seiko Group consists of Seiko Holdings Corporation ( Seiko ) , Seiko Instruments Inc. ( SII ) , and Seiko Epson Corporation ( Epson ) .