Yuka Kishimoto, a receptionist at Numata Trading, has lived a modest yet warm life with her father since losing her mother at a young age. One day, her close friend Chie asks her a sudden favor: "Can I stay at your place for a while?" Though momentarily hesitant, Yuka agrees, determined to help her friend. A few days later, returning home from work, Yuka is confronted with an unimaginable situation. From that moment on, her everyday life is completely turned upside down.