It looks like a standard marked deck of cards.

They are called Magic Cards:

MAGIC CARDS (available only in Japan)

A spectator selects a card, returns it to the deck, and thoroughly mixes the cards. Nonetheless, the magician is able to pull out the spectator's selected card by simply running his fingers along the edge of the deck. The cards also contain secret marks that allow the magician to determine the spectator's card.

http://www.tenyo.co.jp/magic_en/catalog/index.html

Development Story:

This trick has been in existence for ages, and the creator is therefore unknown. When producing these cards, we carefully considered how to mark them in such a way that the marks would be invisible to spectators, but instantly readable by the magician. The back design we developed may indeed be the last word in marked cards.

Richard

It's a marked stripper deck. I believe the marks use DeLand's clock principle.