Some 2,300 years ago in the Archean Era, a strangely sparkling ball fell from the night sky in Japan. People named the ball Pako. Pako, is in fact a time capsule that is a treasured casket of super civilizatioon or a message of civilization from a metamer planet that contained the detailed knowledge of science, medicine, politics, economy that will be useful to human beings when they are in peril in the twenty-first century.
Prince Shotoku saw that it was something to be kept in awe, and ordered a ninja squad to guard it. It has been handed down in secret by ninja from generation to generation. Now, Toha Yamaji, the protagonist is in charge of the clay disk, which is the only clue to the location of Pako.
Those who are looking for the Pako a re not limited to these governmental secret agents. The great capitalist classes, Mafia, underground organizations even individuals and thieves who want to become the supreme ruler of the world flock to Japan. Will Toha be able to protect the clay disk from other veteran ninjas from all over the world ?