Kyoto district public prosecutor Tsurumaru Aya celebrates her 50th birthday and is in good spirits. Then, her mother-in-law, Keiko, suddenly arrives from Tokyo. Aya acts firmly with all violent criminals, but she is no match for Keiko and grows irritated. Meanwhile, the dead body of Iijima Yasushi, who runs a landscape gardening business, is discovered. It appears from the situation at the crime scene that his death had been disguised as an accident by a bolt of lightning, and suspicions of murder grow. Before long, Hayashi Mineo, a Japanese artist active in China, emerges in the investigation. Aya, who visits Mineo, takes note of his damp shoes...