Newly hired Kana Momonoki secretly harbors a fascination for older men and instantly falls for her department's Section Chief Ozawa. Despite her innocent appearance, she takes bold actions—pressing close, whispering seductively, and repeatedly tempting him to win his heart. Though Ozawa is a married man with a wife and child, he succumbs to Kana's irresistible charm and gives in to passion, having sex with her on the fifth day, a Friday night. From that moment on, a heated erotic story unfolds between the young newcomer and the older man. Rather than pure romance, adult desires intertwine as their relationship gradually deepens.