Yui, a young girl pawned to an antique pawnshop to settle her parents' debt, is forced into a cruel existence. With no right to refuse, she endures monthly "interest payments" in the form of perverse treatment from the shop's head clerk and servants. Day by day, she is subjected to a relentless, insidious form of breeding—her spirit slowly broken under systematic humiliation, bondage, enemas, rape, and BDSM. Her suffering extends far beyond mere debt, plunging her into overwhelming torment and inner conflict.