National Treasures & Important Cultural Properties
of National Institutes for Cultural Heritage, Japan

Ryubinnomushiro is a square shaped (in its current condition) Imushiro (rush matting) and represents four Ka-mon (patterns) on the surface using dyed rush and decorated with cloth covers on the edge. The Ka-mon patterns are presented in yellow, pale blue and dark purple and the yellow part is presumed to be made from straw. It currently has fading colors, soiling and damage, but the damaged parts have been repaired by applying pieces of Nishiki (woven fabric), which indicates it has been taken good care of.

When looking at the back of this item, two parts are connected near the center. This indicates that consideration was given to obtaining a good finish by using the best part of the rush grass for an even diameter.

There are two types of Nishiki that cover the edges. They are both red Yoko-Nishiki with Uki-mon (floating patterns), but they seem to be Nishiki from the Middle Ages and therefore are different from Yoko-Nishiki from the Nara period. As the Ka-mon patterns of the rush grass are cut down in half and it are decorated with cloth covers on the edges, it seems that a long Imushiro (rush matting) was cut and decorated with the cloth to make the current shape. It is presumed to have been made in the Kamakura period due to Nishiki used to cover the edges. Nearly square shaped Ryubinnomushiro (important cultural property) remain in Horin-ji Temple in Nara and rush grass dyed in red, green, pale blue, purple and straw (this part looks shiny) is used and the four edges are decorated with Karakusa-mon (Chinese grass pattern). On the inside of the decoration, there is a tree represented in the center and Ka-mon patterns are presented at the both sides. This item and the one held in Horin-ji Temple are common in the points where dyed rush grass and straw are used and the "Ryubinnoshiro" is connected at the back, but the one held in Horin-ji Temple has more complex and sophisticated patterns.