While traveling alone and staying at a minshuku, a man named Kohei accidentally meets a beautiful woman named Yoshino Tsubaki, who's staying in the next room. Charming in both appearance and personality, Tsubaki captivates Kohei's heart. Meanwhile, Tsubaki, who had come on a solo trip under the pretext of visiting her husband's grave, secretly finds herself drawn to Kohei. Aware of their mutual feelings, the two give in to their rising emotions and share an intensely intimate time together. What emerges between them evolves into something deeper than mere romance. Their relationship holds the irreversible possibility of crossing a line—leading to an ending that will leave viewers profoundly shocked.