Office lady Mariko was puzzled that her boyfriend Junichi suddenly left for a remote country. Junichi volunteered as an international volunteer to teach children in developing countries, and he will not return for another two years. Junichi had decided to do such an important thing without consulting himself or his family...what was the reason? With no phone service, all Mariko can do is to write a letter to Junichi expressing her anxiety.

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.

Ryusuke Tsukumo is a quirky, yet brilliant neuroscientist working for the National Research Institute of Police Science. Wielding a unique perspective and psychology, Tsukumo tackles the nation's most baffling crimes and scandals, going head-to-head with the most brilliant and twisted criminal minds. But his eccentricities and poor social timing can also aggravate people and circumstances, further complicating matters.

Miki Ichinose is a 14-year-old schoolgirl who is very outgoing and cheerful. She lives with her parents and younger brother. She is in a romantic relationship with Satoshi Kirino who is 15 years old. They keep their relationship a secret from their parents because Miki is young and Satoshi is expected to excel in school and get into a university so he can take over the family business by his overbearing mother. One night, after a date, they sneak into a treehouse and consummate their relationship. Soon after, Miki suspects that she is pregnant and steals a pregnancy test, which her mother later finds. She is taken to a doctor who confirms her pregnancy. Initially upset, Miki's parents promise they will support her. Miki tells Satoshi of the pregnancy and he takes the news well. However, his mother is furious when she learns of it and forbids the two from seeing each other.

The series is about a girl suffering from multiple personality disorder.