The wealthy Mimura family's peace is shattered when Hayato, Yukio's cousin, arrives with a sinister proposal. Revealing a dark ancestral tradition of a "woman breaking" contest used by their fathers to claim the family fortune, Hayato challenges Yukio to a similar competition. To protect the estate, Reika agrees to be the subject of the contest, only to find herself trapped in a sadistic game of psychological and physical manipulation as Hayato attempts to strip away her loyalty to Yukio.
As the "woman breaking" contest intensifies, Reika discovers a craving for extreme pleasure that normal intimacy cannot satisfy. Yukio attempts to reclaim her by utilizing BDSM techniques discovered in his father's secret diary, but his efforts are cut short by a cruel betrayal. On the final day of the competition, Hayato orchestrates Yukio's downfall, seizing control of the Mimura estate and claiming a broken Reika as his prize.