During the peak of Japan’s sumptuous dynastic culture in the Heian Period,
Kaiawase (the clam shell game) began.
This game involved competing to compose the most refined Waka (31-syllable Japanese poems)
while moving 360 clamshells from left to right.
Inside each clamshell were colorful miniatures depicting the Tale of Genji and Kacho
(literally flowers and birds). Combining a shell and its lid perfectly was only possible in one combination;
this was said to represent Wago (harmony) and a woman’s chastity.

Songs and stories were transcribed onto Tsugigami (literally joined paper).
More than two pieces of paper with different textures or colours were joined together
to give the impression of a three-dimensional structure and transforming colours,
on which sentences were written.
During the Heian Period, when paper was precious,
aristocratic women and their ladies-in-waiting are said to have made this paper.
A delicate aesthetic sense as well as a sense of humor can be visualized in the paper.
Inside the Kaiawase the image of Tsugigami are depicted.