Returning home for summer vacation, Sol encounters a mysterious man named Romi. When an uncomfortable cohabitation begins with him, who seems to be her mother’s boyfriend, Sol finds herself caught in a web of constant suspicion and misunderstanding. Yet, as they spend time together, Romi’s genuine feelings gradually come to light, colliding with Sol’s conflicts with her mother and her childhood friend Dohyun’s feelings for her. Entangled in both excitement and confusion, a sweltering midsummer story of misunderstandings and heart-fluttering moments unfolds.