“Sumire Hair Salon,” a play by Zainichi playwright and director Jeong Ui-sin, 69, tells the story of an ethnically Korean family living in a coal-mining town in Kyushu, Japan, in the 1960s. At the center of the story is Sumi, the second of three sisters, who dreams of opening a hair salon. A series of tragedies unfolds, including a mining accident and seizures caused by carbon monoxide poisoning. In the midst of all this despair, however, Sumi’s…