Kotetsu (虎徹) is a servant of Mikage Shrine known as the onibi-warashi (鬼火童子 Translation: Will-o'-the-Wisp Child). He serves Nanami with the help of Onikiri.
Kotetsu has a very joyous and happy personality. He is also very caring and he worries about Tomoe and Nanami's well being. His personality is very similar to Onikiri and they often act and speak in perfect synchronisation.
- Mystery beneath the mask; from the anime, it was shown that Kotetsu's face is a mask, however what lies under the mask was not revealed in the anime. nor the manga Whatever lies beneath the mask Tomoe felt obliged to apologise for seeing.