On their 30th-anniversary celebration, a woman is unaware that her husband, Osamu, is planning to publicly announce their divorce with his lover. While the mistress schemes for a humiliating photo, the wife straightens his collar, oblivious. At the party, Osamu declares their marriage a 'mistake.' His lover mocks the wife, revealing the husband's longtime resentment. In the wake of the public betrayal, the wife confronts her husband and the mistress, accusing them of destroying her past dreams and vowing to reclaim everything they stole from her, shifting from a victim to a determined challenger.