Legion

is a Japanese light novel series written by Tomonori Sugihara, with illustrations by Yamato Engi. The series began publication on April 10, 2007 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
I, Toru Kazami picked up a notebook in the library. The owner is Aoi Yajima, who is beautiful but isolated in the class, and a mysterious story is spelled inside. A strange "sleeping sickness" begins to prevail in the world, and at the same time, the story of Aoi changes. And I begin to feel a sense of discomfort in the world.

I, Toru Kazami have become a knight who controls the only weapon "Knight" that can counter the "different sea". While fighting against the "different sea" that causes "sleeping sickness" and erodes the world, I begin to doubt my past. What is the interlaced "I" and "I", and the connection between the two worlds?