丹 means 'rust' or 'vermilion'

Nature abounds in these essays, including blood-red sunsets, brightly colored birds, and fall foliage. Logically, art forms such as painting, calligraphy, and lacquering also emerge as central themes. But who would have guessed that color ties in with many body parts: blood, the eye, lips, skin, cells, and even a point where energy is concentrated. Mental states also matter here with faces flushed with rage, diligence in work, depression and lifelessness, and vitality. Moreover, multiple essays touch on religion, minerals (including one ingested for longevity), and old forms of currency (one of which was chocolate!).

In this bouquet of essays, flowers represent far more than beauty. Those showcased here (including the Chinese bellflower of the 梗 essay and the tree peony of the 丹 essay) symbolize everything from the emperor, nobility, and wealth to honor, love, and feminine beauty. The Japanese also associate some of these flowers with hardiness or with grief. People celebrate them in family crests, at festivals, with dolls, and in a range of artistic creations. Supposedly, the flowers even confer health benefits—curing headaches, cooling and invigorating the blood, and removing phlegm.