Shōnen Onmyōji (少年陰陽師) also known as The Teen Exorcist is a Japanese light novel series written by Mitsuru Yūki and illustrated by Sakura Asagi.

On July 3, 2008, Funimation announced that it had struck a deal with Geneon to distribute and release several of their licenses, including Shōnen Onmyōji.

One day, Masahiro meets a fox-like creature which he names Mokkun (もっくん) who shows him his true potential powers after fighting a demon.

He is one of the twelve shikigami called the Shinshō (神将), who has pledged his loyalty to Seimei and is helping Masahiro to surpass his grandfather.

Not only does he have to convince the other Shinshō that he is Seimei's true successor, he must also increase his power in order to stop demons coming from China, the other parts of Japan and the Underworld.

In addition to this he has to deal with the schemes of rival onmyōji who want to destroy Japan not to mention keeping his promise to protect Princess Akiko of the Fujiwara clan.

He arrives in Japan and plans to eat Fujiwara no Akiko to replenish his spirit powers and heal his wounds.

Someone is trying to open the gate to the underworld, events from fifty-five years ago reoccur, and Guren as well as Masahiro must undergo the ultimate test.

The Shiou Arc (尸櫻編, Shikabane sakura (shi ō) Hen) starts from volumes 32 to in the novel.