Monochrome Factor

is a Japanese manga series written and illustrated by Kaili Sorano. It was first serialized in Mag Garden's bi-monthly manga magazine Comic Blade Masamune in May 2004. However, when the magazine ceased publication, the manga began serialization in the new and revamped magazine, Comic Blade Avarus, in September 2007.

The manga is licensed for distribution in North America by Tokyopop, and has so far released four volumes, with the latest having been released on December 2, 2008.

An anime adaptation produced by GENCO, and animated by A.C.G.T, premiered on Japan's terrestrial television network TV Tokyo on April 7, 2008. It also aired on other networks such as AT-X and TV Osaka, though the episodes aired on TV Tokyo first. The anime has shōnen-ai themes which are almost completely absent from the manga.

Plot
The story revolves around the high school student Akira Nikaido, a typical slacker living a normal life. That is, until he meets the mysterious Shirogane, a man who suddenly appears and tells him that they have a destiny together. When Akira hears this, he is shocked and doesn't believe a word of it. Suzuno Aya, a friend of Akira, forgets something in the school one night, and asks Akira and Kengo to help her and go find it. He agrees, and while there, he gets attacked by a shadow monster. Shirogane convinces him that the balance between the human world and the shadow world has been distorted and that Akira must become a "shin"- a creature of the shadow world- in order to help restore the balance. But if Akira stays as a "shin" he will become a shadow himself, and normal people will not see him any more. Shirogane wanted to be with him and lied that if he became his shadow he will be seen by other people again. Soon after a person called "master" told Akira that he did not need Shirogane to become his shadow because he has an object that if he steps on it is will become his shadow,which made Akira angry at Shirogane. After, Akira notices that his friends Aya and Kengo could see Akira and Shirogane when they are "shin," so Akira decides that the two could join them and help Akira and Shirogane to get the balance back to normal...