While conducting a crackdown on contraband cigarettes at Ueno Station, inspector Tetsuro Shibuya came across an envelope addressed to Misa Makihara inside an unattended backpack filled with loose tobacco. Misa was ostensibly an employee of Yamagishi Shokai, a real estate firm, but in reality she was the mistress of Yuzo Yamagishi, a cigarette bootlegger. Yamagishi’s contraband cigarettes were made from loose tobacco sourced from Misa’s uncle, Kisaku, in Ibaraki.