In an Asian nation, a dictator dies suddenly. His family is executed, but his young daughter, Princess Pirufa, is spirited out of the country by one of her father’s trusted aides. In time, that same aide seizes power and decides to install the princess as queen. A request arrives at the office of a private detective named Takeshi in Tokyo: find the princess. There is one catch—whenever the princess becomes excited, a snake-shaped birthmark appears on her lower abdomen. Developing a secret device to help him locate this mark, Takeshi sets out on his investigation…