In Japan, irises are symbols of heroism. The iris plays a key role in the Japanese spring festival for boys, because of its blue color, which suggests "blue blood". (1) Iris are sometimes called "shoubu" which has the same sound as the words for "toward" and "warrior". This is why the iris also suggests heraldry and royalty.

In rural parts of Japan, the roof iris (Iris tectorum) is believed to give protection from storms and typhoons and was therefore frequently planted in roofs. (2) Another kind of iris, the kakitsubata, signal the presence of shallow water and the lowlying plank bridges, yatsuhashi. This kind of iris is the most celebrated in Japanese art. (3)

In China, the iris is believed to ward off evil spirits and diseases. Disease-fighting ceremonies were held on the fifth day of the fifth lunar month, which always included the iris. (4)