Kidoumaru

A hideous demon with a large horn on its head.

The code name given by the Magic Defense Squad was "Single Horn," and Kidoumaru was the name given by Aoba.

It once caused a magical disaster known as the "Tsukiyama Oizawa Incident," which destroyed Kyouka's hometown. For Kyouka, it was a detested enemy.

In the main story, it was subdued by Aoba and became a servant. During the battle in the hidden village, it fought one-on-one with Kyouka, but was freed from Aoba's control by an intrusion from Shikoku, injuring Aoba and attacking Yuuki and Kyouka. However, it was overpowered by the enslaved Yuuki and Kyouka, and was defeated after receiving Kyouka's sword technique "Disordered Mountain Cherry Blossoms."