Sakura and Shin are struggling to keep their detective agency afloat. Day after day, debt collector Kondo shows up, disrupting their work. One day, Kondo kidnaps Sakura and attempts to assault her, but Shin rescues her just in time. A few days later, a delivery job comes to the office, and Sakura's younger sister Mai accompanies her to the destination—only to encounter an unexpected and horrifying turn of events.