Rei Aoki has been married for five years, living a comfortable life without any major troubles. However, the monotony of her daily routine gradually wears her down, leaving her feeling bored and unfulfilled. One day, she receives a wedding invitation from her best friend. Attending the ceremony, Rei watches the happy couple and is reminded of her own loneliness and dissatisfaction, feeling a deep sense of emptiness. There, she's approached by Ozawa, a friend of the groom. Drawn to his kindness, she agrees to go with him to a bar. Under the influence of alcohol, their encounter escalates into passionate sex. Though they part ways afterward, Rei unexpectedly runs into Ozawa again one night while drinking alone.