We are in the Taishō Era (1912–1926). Sumie, the only daughter of a once-proud warrior clan now fallen from grace, is to marry into the respected Hikashi family, a union intended to restore the lost prestige of her own lineage, the Kanemoto clan.

Yet before even meeting her future husband, the naive and inexperienced Sumie must first test her resolve by immersing herself in the moral decay of her new home.