魔性の子 [Mashō no Ko]

The book that spawned the Twelve Kingdoms series!

When student teacher Hirose comes back to his alma matter for a few weeks, he notices one student in particular, Takasato Kaname, who stands out in a strange way. The other students seem to be doing their best to pretend Takasato isn't even there. Then Hirose finds out from some of them that Takasato was "spirited away" and mysteriously reappeared a year later with no memories of where he had been or what had happened during that time.

They also tell him bad things happen to people who mess with Takasato. Hirose soon witnesses this for himself as the consequences grow ever more severe and horrifying.

Chronologically this novel takes place after the fourth Twelve Kingdoms book, Skies of Dawn (風の万里 黎明の空; Kaze no Banri, Reimei no Sora) and some events are covered in book six (黄昏の岸 暁の天; Tasogare no Kishi, Akatsuki no Sora).