Hiroko Terada

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.

Natsumi's (Hikaru Takahashi) younger sister Haru passes away because a disease. She was just 19. Natsumi loved her younger sister a lot. Meanwhile, Haru was engaged to Togo. Togo comes from a distinguished family, who runs a large company. His parents care about pedigree a lot and suggests to Natsumi that she should now date Togo. Natsumi turns down their request, but Toho accepts his parents request to date Natsumi. Suddenly, Natsumi asks Togo to take her to places where he took her younger sister. Togo is surprised by her request, but he begins to take Natsumi around. Natsumi soon becomes attracted to Togo, but she feels a sense of guilt for her feelings.

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.