This design is not directly related to the Hyakunin Isshu work that I was doing at that time; this is a reproduction of one from a set of 72 game cards based on the '36 Famous Poets', yet another of those numbered ranks of famous objects - people, scenery, poems, etc. - that the Japanese of old were so fond of.

For the origin of this sort of game, we have to look back to the Heian era, to some of the games then fashionable among the nobility. From what we know of the daily life of this class, many of their days must have been extremely long and dreary indeed, living in prescribed locations, in prescribed clothing, and able to speak only to certain people. Perhaps as a result of this enforced idleness, certain games came into fashion, games which of necessity utilized many of the things with which these people were surrounded - calligraphy, literature, poetry, etc. One very popular game was the 'matching' game. On two similarly shaped slips of card (or on the two halves of a sea shell, for those who could afford such things), would be painted matching scenes, perhaps flora and fauna, or perhaps something with literary allusions. Large sets of these would be spread out face down on the floor to test everyone's ability to match them up, exactly the same way that children still do today with playing cards.

Somebody somewhere - we have no idea who - had the idea of using the two halves of a poem as the basis for the matching challenge, and the game of karuta was born.

(More about the history of the game in my presentation here).