During summer vacation, Sol encounters Romi, a mysterious man who seems to be her mother’s boyfriend. As their uncomfortable cohabitation begins, Sol becomes entangled in endless doubts and misunderstandings. Over time, Romi’s true feelings, conflicts with her mother, and even the emotions of her childhood friend Dohyun come into play. Sol’s heart grows increasingly confused, and a bittersweet story of one summer filled with excitement, misunderstandings, and emotional turmoil unfolds.