He was an ordinary young man with almost no experience with women and few friends, trapped in a monotonous daily routine. One day, Yui, a married woman he met at his part-time job, suddenly proposed a physical relationship. Initially, he took it half-jokingly, but she confessed that despite being newlywed, she was suffering from a sexless marriage and harbored intense desires. That moment sparked a physical relationship between them, drawing them powerfully toward each other. This single step became the turning point that drastically changed both their fates.