Shirou Kougetsu is your ordinary, run-of-the-mill Japanese mystery novelist. He writes novels, goes on wacky adventures with teenage sidekicks, and assists the police with actual murder investigations. You know, the usual. One day a college friend, Yuika (who’s a pretty young woman, obviously), tells Shirou that she recently got an odd reading at a psychic and feels a spirit has been following her ever since. In order to learn about this spirit, she asks Kougetsu to accompany her to visit a medium—the mysterious, delicate, and stunningly beautiful Hisui Jouzuka.
At the meeting Hisui demonstrates her powers, warns Yuika that she’s in danger, and asks to make a home visit to investigate further. However, when Hisui and Kougetsu go to visit Yuika, it’s too late—she’s been murdered in her apartment. The police suspect a break-in gone wrong, but Hisui tells Kougetsu that the culprit is a woman. Thus begins a partnership between medium and novelist: Hisui forms a conclusion using her power, and then Kougetsu uses his knowledge and experience as a mystery novelist to find evidence to back up Hisui’s findings (since they can’t just go to the police and directly report Hisui’s magic powers).
As Kougetsu and Hisui solve cases, we see interludes from the perspective of a serial killer who has been abducting and murdering beautiful young women. He’s extremely methodical and careful, and thus has avoided leaving any traces or clues for the police so far. He’s convinced himself that the only way someone would be able to catch him is with supernatural powers….
I hated Medium when I was reading it. I loved Medium when I finished.