Keiko Akiyoshi, wishing to help her daughter's troubled marriage, always stepped in between her daughter and son-in-law to encourage dialogue and resolve conflicts. However, her efforts inadvertently began to destroy the couple's relationship. One day, when Keiko visits her daughter's home, she finds herself drawn into a seductive encounter with her son-in-law at night. In that moment, she should have scolded him and urged him to cherish her daughter. Instead, Keiko's heart is shaken by his forceful advances, making her confront her own hidden emotions. Her attempt to save the marriage ends up pulling her into the turmoil herself, and that single moment of hesitation becomes the turning point that changes everything.