The suspense story begins when Jin Saeki, a policeman in Yamanashi Prefecture, arrives at a prominent estate residence in response to a tip, and finds the skeletal remains of 13 children, as well as a mysterious marking. Jūzō Haikawa, the long-missing owner of the estate, immediately becomes the prime suspect. Saeki collaborates with a woman named Kanon Hasumi, who has a connection to Haikawa, and together they search for the truth behind the case. In a parallel story set in Tokyo seven years after the case, a girl with a connection to the mark left on the Haikawa estate runs away from home.

Takeshi Hongo is a promising young man with a passion for motorcycle racing. However, his dreams are suddenly ruined when he gets kidnapped by Shocker, the evil secret organization planning to dominate the world. After being remodeled into a cyborg, Takeshi escapes and swears to protect the world from the inhuman monsters.