Michio Hayasaki is an excellent engineer for a medical instrument manufacturing company. For years he has been working very hard, by day and night, trying to develop a wheel-chair robot which could assist persons with general paralysis, but in vain. The completion of this type of robot is really anticipated by company executives, seeing that ten years ago, Hayasaki invented a special tonometer for measuring blood pressure, which became a big hit and brought a great deal of profit to the company.

As a matter of fact, Hayasaki is tormented by stress. Then, one night at home, he gets frightened on finding his own 'double' standing in front of him! Hayasaki understands that he is his 'doppelganger', and is reminded of the saying that anybody who has seen their own double is destined to die soon.

Despite Hayasaki's concerns, his doppelganger starts behaving in astonishing ways. The first action he does is to destroy his laboratory. He is very sympathetic towards Hayasaki's agony and tries to do every possible action to relieve him of various types of stress and let him succeed in finishing the robot. He therefore seduces Hayasaki's assistant colleague, Takano (Hitomi Sato); kills a man to rob him and provide Hayasaki with money for study fees; and even brings Hayasaki the latest data for robots.

Hayasaki's doppelganger then kills the doppelganger of the younger brother of a certain woman, Yuka Nagai (Hiroki Nagasku), one of Takano's friends. Yuka one day becomes stunned to find her brother, Takashi (Eisuke Suzuki) in his room soon after the police have informed her of Takashi's suicide. Obviously it was Takashi's doppelganger that has come home. To relieve Yuka's fears and worries, Hayasaki's doppelganger beats Takashi to death by hitting him on the head and buries him on the sea shore, and reports to her that Takashi's doppelganger has gone to America.

Meanwhile. Hayasaki gets laid off, as he was naturally seen as responsible for destroying his own laboratory, but his doppelganger finds Hayasaki a new laboratory, which used to be a factory. He even employs a new assistant, Kimijima (Yusuke Santamaria) for Hayasaki. Yuka then duly decides to become Hayasaki's new assistant. It seems that she feels that she has been freed from Takashi's doppelganger, after hearing the news that Takashi's doppelganger is now in the United States.

In cooperation with Hayasaki's doppelganger, Kimijima and Yuka, the robot is duly been completed. Now confronting his doppelganger concerning leadership over the robot, Hayasaki kills him together with Kimijima, discarding his body in a hole under the factory floors. Hayasaki, Kimijima and Yuka head for Nigata to sell the robot at a big company in a van.

This is merely one third of the story....