Married woman Yoriko (38 years old). After 15 years of marriage, living as a full-time housewife, she finds herself increasingly lonely as her child grows up and emotional distance grows between her and her husband. Her husband, a classmate from middle school, has been her partner since ninth grade, and they've shared 25 years together. Recently, however, his strange behavior has troubled her deeply, prompting her to make a bold decision: a two-day, one-night trip with a man she's never met before. Betraying the man she's spent decades with, she lies in a foreign room, staring at an unfamiliar ceiling, tormented by conflicting emotions. As the journey unfolds, she begins to understand feelings she's never experienced in 25 years—emotions that grow stronger with each passing moment.