Large bronze mirrors became popular around the Genroku era of Edo. These mirrors bear the "Tenka-ichi" (Best in the World) mark and the names of the makers: Fujiwara Yoshinaga, Yoshitsugu, and Yoshishige (three mirrors). From the mid-Edo period, bronze mirrors with a diameter of 20 centimeters or more, used as full-length mirrors, became common. Although they were expensive at the time, they were often used for wedding trousseaus and celebrations, and the designs included traditional motifs like pine, bamboo, plum, crane, and turtle, along with celebratory characters. It seems that mirror polishing craftsmen existed to polish the mirror surfaces and keep them clean, removing any clouding or scratches. Without maintenance, copper will blacken and develop verdigris over time due to aging. The appeal of bronze mirrors lies in their historical Japanese designs. These are antique items from several hundred years ago, so please refrain from purchasing if you are overly concerned about their condition.