Mayumi (Mitsumune Kaoru), who works for a publishing company, happens to meet a mysterious man who calls himself Shindo (Nakamura Tomoya). Told by a fortune teller that she will have a “destined meeting”, she pays attention to this. But what awaits her is ironically an encounter with Ushijima Kaoru (Yamada Takayuki), the boss of Cowcow Finance, is known as a legendary black market lender. Cowcow Finance lends money at an illegally high interest rate of 5% every 10 days and relentlessly corners bad debtors.