Uno and her husband Masashi have been happily married for three years, and they are finally ready to start a family. Eager to conceive, Uno prepares for a romantic evening during her most fertile days, only to have their plans derailed when her husband's younger colleague, Oki, drops by for an unexpected visit. The night ends in disappointment as Masashi gets too intoxicated to perform, leaving Uno frustrated and longing for the intimacy she had carefully planned. The situation takes a dark turn the following day when Oki returns, claiming he left an item at a local hotel and manipulating Uno into retrieving it for him.
Upon arriving at the hotel room, Uno finds herself cornered by Oki, who forces himself upon her, ensuring he ejaculates deep inside her during her peak ovulation window. Traumatized and desperate to reclaim her marriage, Uno returns home and demands that her husband be intimate with her repeatedly, hoping to overwrite the encounter with Oki. However, the cycle of coercion begins when Oki reappears, threatening to expose the affair to Masashi unless she complies with his demands. Trapped by his blackmail, Uno is forced to meet Oki at the hotel every month during her fertile period, effectively turning her secret into a recurring nightmare of forced infidelity.
Months later, the deception reaches a breaking point when Uno becomes pregnant. While Masashi is overjoyed at the prospect of becoming a father, Uno is haunted by the reality of her situation. She has spent the last month avoiding intimacy with her husband, knowing full well that the child she carries is likely the result of her forced encounters with Oki. This intense drama explores the complex intersection of betrayal and unwanted pregnancy, leaving viewers to witness the devastating consequences of a secret that threatens to destroy a seemingly perfect marriage forever.
