Yamada, an elderly man living alone, collides with a black gyaru named Sara on the street one night and faints. Sara panics, performs emergency first aid, and saves him. Witnessing the scene, she quietly leaves once assured he's okay. However, Yamada notices Sara dropped her business card case. Wanting to express his gratitude to his rescuer, he calls the number written on the card. From there, an unexpected turn of events begins.