With my parents away on a trip starting today, I was left alone at home, lazing around with nothing to do. Then suddenly, the doorbell rang. Sighing at the inconvenience, I opened the door to find my childhood friend Hiyori standing there. Carrying a large bag, she pleaded with me, "Please let me stay for three days starting today! Don't ask any questions—just say yes!" With my parents out of the house, a temporary cohabitation game begins between Hiyori and me. An impure relationship unfolding as an extension of daily life. Spending time together felt like living through uniquely special days, so enjoyable I couldn't get enough. Our relationship naturally progressed, and feelings we never expected to surface quietly began to grow. In the small gaps of ordinary life, a pure romantic spark was born.